diff --git a/installer/windows/calibre/calibre.mpi b/installer/windows/calibre/calibre.mpi
index 6ad18ddaf1..a5fc37d883 100644
--- a/installer/windows/calibre/calibre.mpi
+++ b/installer/windows/calibre/calibre.mpi
@@ -534,8 +534,6 @@ File ::8B8655B8-3823-AA02-1CDA-02F5AD4677C0 -name fetch-ebook-metadata.exe -pare
 File ::8FC3D58A-F3FA-A2D1-711F-F4C3128620CE -name podofo.dll -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
 File ::88034147-A376-B759-D48C-5F17A47E8CC3 -name ebook-meta.exe.local -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
 File ::6E6F2A97-6614-F2A6-1751-95C099B909FD -name pdfmanipulate.exe.local -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
-File ::AC456A9A-6653-5852-D1F7-B04E2C1AA481 -name isbndb.exe -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
-File ::94580010-4CE4-8EC0-3834-9A2BCCB28C70 -name isbndb.exe.local -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
 File ::BA087530-7CF4-5460-C9AA-DE4A796C9AEB -name pdfmanipulate.exe -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
 File ::6AF80BFC-A813-074D-897A-856744A91949 -name ebook-convert.exe.local -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
 File ::F8C59A30-9E90-0861-5604-95E7C69C3C80 -name ebook-convert.exe -parent 8E5D85A4-7608-47A1-CF7C-309060D5FF40
diff --git a/src/calibre/constants.py b/src/calibre/constants.py
index 319b01f887..75912b276d 100644
--- a/src/calibre/constants.py
+++ b/src/calibre/constants.py
@@ -2,7 +2,7 @@ __license__   = 'GPL v3'
 __copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
 __docformat__ = 'restructuredtext en'
 __appname__   = 'calibre'
-__version__   = '0.6.0b3'
+__version__   = '0.6.0b5'
 __author__    = "Kovid Goyal <kovid@kovidgoyal.net>"
 
 import re
diff --git a/src/calibre/devices/prs505/books.py b/src/calibre/devices/prs505/books.py
index 6e268e734a..c10263c6e0 100644
--- a/src/calibre/devices/prs505/books.py
+++ b/src/calibre/devices/prs505/books.py
@@ -403,8 +403,9 @@ def fix_ids(main, carda, cardb):
         for child in db.root_element.childNodes:
             if child.nodeType == child.ELEMENT_NODE and child.hasAttribute('id'):
                 id_map[child.getAttribute('id')] = str(cid)
-                child.setAttribute("sourceid",
-                    '0' if getattr(child, 'tagName', '').endswith('playlist') else '1')
+                child.setAttribute('sourceid', '1')
+                #child.setAttribute("sourceid",
+                #    '0' if getattr(child, 'tagName', '').endswith('playlist') else '1')
                 child.setAttribute('id', str(cid))
                 cid += 1
 
diff --git a/src/calibre/ebooks/__init__.py b/src/calibre/ebooks/__init__.py
index d2d6fc94e1..a084cdd0f8 100644
--- a/src/calibre/ebooks/__init__.py
+++ b/src/calibre/ebooks/__init__.py
@@ -25,7 +25,7 @@ class DRMError(ValueError):
 BOOK_EXTENSIONS = ['lrf', 'rar', 'zip', 'rtf', 'lit', 'txt', 'htm', 'xhtm',
                    'html', 'xhtml', 'pdf', 'pdb', 'prc', 'mobi', 'azw', 'doc',
                    'epub', 'fb2', 'djvu', 'lrx', 'cbr', 'cbz', 'oebzip',
-                   'rb', 'imp', 'odt']
+                   'rb', 'imp', 'odt', 'chm']
 
 class HTMLRenderer(object):
 
diff --git a/src/calibre/ebooks/metadata/__init__.py b/src/calibre/ebooks/metadata/__init__.py
index 4c2c6c744a..81275b4ff6 100644
--- a/src/calibre/ebooks/metadata/__init__.py
+++ b/src/calibre/ebooks/metadata/__init__.py
@@ -63,14 +63,13 @@ def roman(num):
 def fmt_sidx(i, fmt='%.2f', use_roman=False):
     if i is None or i == '':
         i = 1
-    i = float(i)
+    try:
+        i = float(i)
+    except TypeError:
+        return str(i)
     if int(i) == float(i):
         return roman(int(i)) if use_roman else '%d'%int(i)
-    try:
-        return fmt%i
-    except TypeError:
-        return fmt%float(i)
-
+    return fmt%i
 
 class Resource(object):
     '''
diff --git a/src/calibre/ebooks/mobi/writer.py b/src/calibre/ebooks/mobi/writer.py
index d3b494af1d..8e9fc25ebf 100644
--- a/src/calibre/ebooks/mobi/writer.py
+++ b/src/calibre/ebooks/mobi/writer.py
@@ -491,12 +491,12 @@ class MobiWriter(object):
             else :
                 tbsType = 6
 
-            tbSequence = decint(tbsType, DECINT_BACKWARD)
-            tbSequence += decint(0x00, DECINT_BACKWARD)
+            tbSequence = decint(tbsType, DECINT_FORWARD)
+            tbSequence += decint(0x00, DECINT_FORWARD)
             # Don't write a nodecount for opening type 2 record
             if tbsType != 2 :
                 tbSequence += chr(self._HTMLRecords[nrecords].currentSectionNodeCount)
-            tbSequence += decint(len(tbSequence) + 1, DECINT_BACKWARD)
+            tbSequence += decint(len(tbSequence) + 1, DECINT_FORWARD)
 
         else :
             # Determine tbsType for HTMLRecords > 0
@@ -520,12 +520,12 @@ class MobiWriter(object):
             shiftedNCXEntry |= tbsType
 
             # Assemble the TBS
-            tbSequence = decint(shiftedNCXEntry, DECINT_BACKWARD)
-            tbSequence += decint(0x00, DECINT_BACKWARD)
+            tbSequence = decint(shiftedNCXEntry, DECINT_FORWARD)
+            tbSequence += decint(0x00, DECINT_FORWARD)
             # Don't write a nodecount for terminating type 2 record
             if tbsType != 2 :
                 tbSequence += chr(self._HTMLRecords[nrecords].currentSectionNodeCount)
-            tbSequence += decint(len(tbSequence) + 1, DECINT_BACKWARD)
+            tbSequence += decint(len(tbSequence) + 1, DECINT_FORWARD)
 
         # print "record %d: tbsType %d" % (nrecords, tbsType)
         self._tbSequence = tbSequence
diff --git a/src/calibre/ebooks/oeb/base.py b/src/calibre/ebooks/oeb/base.py
index e2a4875399..3e16e73ab9 100644
--- a/src/calibre/ebooks/oeb/base.py
+++ b/src/calibre/ebooks/oeb/base.py
@@ -810,6 +810,12 @@ class Manifest(object):
             r = [x for x in data.iterdescendants(etree.Element) if 'microsoft-com' in x.tag]
             for x in r:
                 x.tag = XHTML('span')
+
+            # Remove lang redefinition inserted by the amazing Microsoft Word!
+            body = xpath(data, '/h:html/h:body')[0]
+            for key in list(body.attrib.keys()):
+                if key == 'lang' or key.endswith('}lang'):
+                    body.attrib.pop(key)
             return data
 
         def _parse_css(self, data):
@@ -1327,7 +1333,9 @@ class TOC(object):
         return len(list(self.iter())) - 1
 
     def next_play_order(self):
-        return max([x.play_order for x in self.iter()])+1
+        entries = [x.play_order for x in self.iter()]
+        base = max(entries) if entries else 0
+        return base+1
 
     def has_href(self, href):
         for x in self.iter():
diff --git a/src/calibre/gui2/dialogs/config.py b/src/calibre/gui2/dialogs/config.py
index 59e148046d..70237548d5 100644
--- a/src/calibre/gui2/dialogs/config.py
+++ b/src/calibre/gui2/dialogs/config.py
@@ -112,19 +112,19 @@ class PluginModel(QAbstractItemModel):
             return QModelIndex()
 
         if parent.isValid():
-            return self.createIndex(row, column, parent.row())
+            return self.createIndex(row, column, 1+parent.row())
         else:
-            return self.createIndex(row, column, -1)
+            return self.createIndex(row, column, 0)
 
     def parent(self, index):
-        if not index.isValid() or index.internalId() == -1:
+        if not index.isValid() or index.internalId() == 0:
             return QModelIndex()
-        return self.createIndex(index.internalId(), 0, -1)
+        return self.createIndex(index.internalId()-1, 0, 0)
 
     def rowCount(self, parent):
         if not parent.isValid():
             return len(self.categories)
-        if parent.internalId() == -1:
+        if parent.internalId() == 0:
             category = self.categories[parent.row()]
             return len(self._data[category])
         return 0
diff --git a/src/calibre/gui2/dialogs/scheduler.py b/src/calibre/gui2/dialogs/scheduler.py
index 47f5a63db0..3b45e9a759 100644
--- a/src/calibre/gui2/dialogs/scheduler.py
+++ b/src/calibre/gui2/dialogs/scheduler.py
@@ -182,12 +182,12 @@ class RecipeModel(QAbstractItemModel, SearchQueryParser):
         self.reset()
 
     def index(self, row, column, parent):
-        return self.createIndex(row, column, parent.row() if parent.isValid() else -1)
+        return self.createIndex(row, column, parent.row()+1 if parent.isValid() else 0)
 
     def parent(self, index):
-        if index.internalId() == -1:
+        if index.internalId() == 0:
             return QModelIndex()
-        return self.createIndex(index.internalId(), 0, -1)
+        return self.createIndex(index.internalId()-1, 0, 0)
 
     def columnCount(self, parent):
         if not parent.isValid() or not parent.parent().isValid():
diff --git a/src/calibre/gui2/library.py b/src/calibre/gui2/library.py
index 21583e8f98..e27ccba82f 100644
--- a/src/calibre/gui2/library.py
+++ b/src/calibre/gui2/library.py
@@ -726,7 +726,7 @@ class BooksView(TableView):
         paths = self.paths_from_event(event)
         event.setDropAction(Qt.CopyAction)
         event.accept()
-        self.emit(SIGNAL('files_dropped(PyQt_PyObject)'), paths, Qt.QueuedConnection)
+        self.emit(SIGNAL('files_dropped(PyQt_PyObject)'), paths)
 
 
     def set_database(self, db):
diff --git a/src/calibre/gui2/main.ui b/src/calibre/gui2/main.ui
index 5d564b5f0c..9ad7dbcc49 100644
--- a/src/calibre/gui2/main.ui
+++ b/src/calibre/gui2/main.ui
@@ -696,7 +696,7 @@
   <customwidget>
    <class>TagsView</class>
    <extends>QTreeView</extends>
-   <header>tags.h</header>
+   <header>calibre/gui2/tag_view.h</header>
   </customwidget>
  </customwidgets>
  <resources>
diff --git a/src/calibre/gui2/tag_view.py b/src/calibre/gui2/tag_view.py
new file mode 100644
index 0000000000..7d9f435fa9
--- /dev/null
+++ b/src/calibre/gui2/tag_view.py
@@ -0,0 +1,151 @@
+#!/usr/bin/env  python
+__license__   = 'GPL v3'
+__copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
+__docformat__ = 'restructuredtext en'
+
+'''
+Browsing book collection by tags.
+'''
+from PyQt4.Qt import QStandardItemModel, Qt, QTreeView, QStandardItem, \
+                     QFont, SIGNAL, QSize, QIcon, QPoint, QPixmap
+from calibre.gui2 import config
+
+class TagsView(QTreeView):
+
+    def __init__(self, *args):
+        QTreeView.__init__(self, *args)
+        self.setUniformRowHeights(True)
+        self.setCursor(Qt.PointingHandCursor)
+        self.setIconSize(QSize(30, 30))
+
+    def set_database(self, db, match_all, popularity):
+        self._model = TagsModel(db)
+        self.popularity = popularity
+        self.match_all = match_all
+        self.setModel(self._model)
+        self.connect(self, SIGNAL('clicked(QModelIndex)'), self.toggle)
+        self.popularity.setChecked(config['sort_by_popularity'])
+        self.connect(self.popularity, SIGNAL('stateChanged(int)'), self.sort_changed)
+
+    def sort_changed(self, state):
+        config.set('sort_by_popularity', state == Qt.Checked)
+        self.model().refresh()
+
+    def toggle(self, index):
+        if self._model.toggle(index):
+            self.emit(SIGNAL('tags_marked(PyQt_PyObject, PyQt_PyObject)'),
+                      self._model.tokens(), self.match_all.isChecked())
+
+    def recount(self, *args):
+        ci = self.currentIndex()
+        if not ci.isValid():
+            ci = self.indexAt(QPoint(10, 10))
+        self.model().refresh()
+        if ci.isValid():
+            self.scrollTo(ci, QTreeView.PositionAtTop)
+
+class CategoryItem(QStandardItem):
+
+    def __init__(self, category, display_text, tags, icon, font, icon_map):
+        self.category = category
+        self.tags = tags
+        QStandardItem.__init__(self, icon, display_text)
+        self.setFont(font)
+        self.setSelectable(False)
+        self.setSizeHint(QSize(100, 40))
+        self.setEditable(False)
+        for tag in tags:
+            self.appendRow(TagItem(tag, icon_map))
+
+class TagItem(QStandardItem):
+
+    def __init__(self, tag, icon_map):
+        self.icon_map = icon_map
+        self.tag = tag
+        QStandardItem.__init__(self, tag.as_string())
+        self.set_icon()
+        self.setEditable(False)
+        self.setSelectable(False)
+
+    def toggle(self):
+        self.tag.state = (self.tag.state + 1)%3
+        self.set_icon()
+
+    def set_icon(self):
+        self.setIcon(self.icon_map[self.tag.state])
+
+
+class TagsModel(QStandardItemModel):
+
+    categories = [_('Authors'), _('Series'), _('Formats'), _('Publishers'), _('News'), _('Tags')]
+    row_map    = ['author', 'series', 'format', 'publisher', 'news', 'tag']
+
+    def __init__(self, db):
+        self.cmap = tuple(map(QIcon, [':/images/user_profile.svg',
+                ':/images/series.svg', ':/images/book.svg', ':/images/publisher.png',
+                ':/images/news.svg', ':/images/tags.svg']))
+        p = QPixmap(30, 30)
+        p.fill(Qt.transparent)
+        self.icon_map = [QIcon(p), QIcon(':/images/plus.svg'),
+                QIcon(':/images/minus.svg')]
+        QStandardItemModel.__init__(self)
+        self.db = db
+        self.ignore_next_search = False
+        self._data = {}
+        self.bold_font = QFont()
+        self.bold_font.setBold(True)
+        self.refresh()
+        self.db.add_listener(self.database_changed)
+
+    def database_changed(self, event, ids):
+        self.refresh()
+
+    def refresh(self):
+        old_data = self._data
+        self._data = self.db.get_categories(config['sort_by_popularity'])
+        for key in old_data.keys():
+            for tag in old_data[key]:
+                try:
+                    index = self._data[key].index(tag)
+                    if index > -1:
+                        self._data[key][index].state = tag.state
+                except:
+                    continue
+        self.clear()
+        root = self.invisibleRootItem()
+        for r, category in enumerate(self.row_map):
+            tags = self._data.get(category, [])
+            root.appendRow(CategoryItem(category, self.categories[r],
+                self._data[category], self.cmap[r], self.bold_font, self.icon_map))
+        #self.reset()
+
+
+    def reinit(self, *args, **kwargs):
+        if not self.ignore_next_search:
+            for category in self._data.values():
+                for tag in category:
+                    tag.state = 0
+            self.reset()
+        self.ignore_next_search = False
+
+    def toggle(self, index):
+        if index.parent().isValid():
+            category = self.row_map[index.parent().row()]
+            tag = self._data[category][index.row()]
+            self.invisibleRootItem().child(index.parent().row()).child(index.row()).toggle()
+            self.ignore_next_search = True
+            self.emit(SIGNAL('dataChanged(QModelIndex,QModelIndex)'), index, index)
+            return True
+        return False
+
+    def tokens(self):
+        ans = []
+        for key in self.row_map:
+            for tag in self._data[key]:
+                category = key if key != 'news' else 'tag'
+                if tag.state > 0:
+                    prefix = ' not ' if tag.state == 2 else ''
+                    ans.append('%s%s:"%s"'%(prefix, category, tag))
+        return ans
+
+
diff --git a/src/calibre/gui2/tags.py b/src/calibre/gui2/tags.py
deleted file mode 100644
index a6772a3b44..0000000000
--- a/src/calibre/gui2/tags.py
+++ /dev/null
@@ -1,173 +0,0 @@
-#!/usr/bin/env  python
-__license__   = 'GPL v3'
-__copyright__ = '2008, Kovid Goyal kovid@kovidgoyal.net'
-__docformat__ = 'restructuredtext en'
-
-'''
-Browsing book collection by tags.
-'''
-from PyQt4.Qt import QAbstractItemModel, Qt, QVariant, QTreeView, QModelIndex, \
-                     QFont, SIGNAL, QSize, QColor, QIcon, QPoint
-from calibre.gui2 import config
-NONE = QVariant()
-
-class TagsView(QTreeView):
-    
-    def __init__(self, *args):
-        QTreeView.__init__(self, *args)
-        self.setUniformRowHeights(True)
-        self.setCursor(Qt.PointingHandCursor)
-        self.setIconSize(QSize(30, 30))
-    
-    def set_database(self, db, match_all, popularity):
-        self._model = TagsModel(db)
-        self.popularity = popularity
-        self.match_all = match_all
-        self.setModel(self._model)
-        self.connect(self, SIGNAL('clicked(QModelIndex)'), self.toggle)
-        self.popularity.setChecked(config['sort_by_popularity'])
-        self.connect(self.popularity, SIGNAL('stateChanged(int)'), self.sort_changed)
-        
-    def sort_changed(self, state):
-        config.set('sort_by_popularity', state == Qt.Checked)
-        self.model().refresh()
-        
-    def toggle(self, index):
-        if self._model.toggle(index):
-            self.emit(SIGNAL('tags_marked(PyQt_PyObject, PyQt_PyObject)'), 
-                      self._model.tokens(), self.match_all.isChecked())
-            
-    def recount(self, *args):
-        ci = self.currentIndex()
-        if not ci.isValid():
-            ci = self.indexAt(QPoint(10, 10))
-        self.model().refresh()
-        if ci.isValid():
-            self.scrollTo(ci, QTreeView.PositionAtTop) 
-
-class TagsModel(QAbstractItemModel):
-    
-    categories = [_('Authors'), _('Series'), _('Formats'), _('Publishers'), _('News'), _('Tags')]
-    row_map    = {0: 'author', 1:'series', 2:'format', 3:'publisher', 4:'news', 5:'tag'} 
-    
-    def __init__(self, db):
-        QAbstractItemModel.__init__(self)
-        self.db = db
-        self.ignore_next_search = False
-        self._data = {}
-        self.refresh()
-        self.bold_font = QFont()
-        self.bold_font.setBold(True)
-        self.bold_font = QVariant(self.bold_font)
-        self.status_map = [QColor(200,200,200, 0), QIcon(':/images/plus.svg'), QIcon(':/images/minus.svg')]
-        self.status_map = list(map(QVariant, self.status_map))
-        self.cmap = [QIcon(':/images/user_profile.svg'), QIcon(':/images/series.svg'), QIcon(':/images/book.svg'), QIcon(':/images/publisher.png'), QIcon(':/images/news.svg'), QIcon(':/images/tags.svg')]
-        self.cmap = list(map(QVariant, self.cmap))
-        self.db.add_listener(self.database_changed)
-    
-    def database_changed(self, event, ids):
-        self.refresh()
-    
-    def refresh(self):
-        old_data = self._data
-        self._data = self.db.get_categories(config['sort_by_popularity'])
-        for key in old_data.keys():
-            for tag in old_data[key]:
-                try:
-                    index = self._data[key].index(tag)
-                    if index > -1:
-                        self._data[key][index].state = tag.state
-                except:
-                    continue
-        self.reset()
-        
-    def reinit(self, *args, **kwargs):
-        if not self.ignore_next_search:
-            for category in self._data.values():
-                for tag in category:
-                    tag.state = 0
-            self.reset()
-        self.ignore_next_search = False
-        
-    def toggle(self, index):
-        if index.parent().isValid():
-            category = self.row_map[index.parent().row()]
-            tag = self._data[category][index.row()]
-            tag.state = (tag.state + 1)%3
-            self.ignore_next_search = True
-            self.emit(SIGNAL('dataChanged(QModelIndex,QModelIndex)'), index, index)
-            return True
-        return False
-    
-    def tokens(self):
-        ans = []
-        for key in self.row_map.values():
-            for tag in self._data[key]:
-                category = key if key != 'news' else 'tag'
-                if tag.state > 0:
-                    prefix = ' not ' if tag.state == 2 else ''
-                    ans.append('%s%s:"%s"'%(prefix, category, tag))
-        return ans
-    
-    def index(self, row, col, parent=QModelIndex()):
-        if parent.isValid():
-            if parent.parent().isValid(): # parent is a tag
-                return QModelIndex()
-            try:
-                category = self.row_map[parent.row()]
-            except KeyError:
-                return QModelIndex()
-            if col == 0 and row < len(self._data[category]):
-                return self.createIndex(row, col, parent.row())
-            return QModelIndex()
-        if col == 0 and row < len(self.categories):
-            return self.createIndex(row, col, -1)
-        return QModelIndex()
-    
-    def parent(self, index):
-        if not index.isValid() or index.internalId() < 0:
-            return QModelIndex()
-        return self.createIndex(index.internalId(), 0, -1)
-    
-    def rowCount(self, parent):
-        if not parent or not parent.isValid():
-            return len(self.categories)
-        if not parent.parent().isValid():
-            return len(self._data[self.row_map[parent.row()]])
-        return 0
-        
-    def columnCount(self, parent):
-        return 1
-    
-    def flags(self, index):
-        if not index.isValid():
-            return Qt.NoItemFlags
-        return Qt.ItemIsEnabled
-        
-    def category_data(self, index, role):
-        if role == Qt.DisplayRole:
-            row = index.row()
-            return QVariant(self.categories[row])
-        if role == Qt.FontRole:
-            return self.bold_font
-        if role == Qt.SizeHintRole:
-            return QVariant(QSize(100, 40))
-        if role == Qt.DecorationRole:
-            return self.cmap[index.row()]
-        return NONE
-    
-    def tag_data(self, index, role):
-        category = self.row_map[index.parent().row()]
-        if role == Qt.DisplayRole:
-            return QVariant(self._data[category][index.row()].as_string())
-        if role == Qt.DecorationRole:
-            return self.status_map[self._data[category][index.row()].state]
-        return NONE
-        
-    
-    def data(self, index, role):
-        if not index.parent().isValid():
-            return self.category_data(index, role)
-        if not index.parent().parent().isValid():
-            return self.tag_data(index, role)
-        return NONE
diff --git a/src/calibre/linux.py b/src/calibre/linux.py
index d9f6b0777e..11884a2e4e 100644
--- a/src/calibre/linux.py
+++ b/src/calibre/linux.py
@@ -334,7 +334,7 @@ def post_install():
         os.chdir(config_dir)
         for f in os.listdir('.'):
             if os.stat(f).st_uid == 0:
-                os.rmdir(f)
+                os.rmdir(f) if os.path.isdir(f) else os.unlink(f)
     if os.stat(config_dir).st_uid == 0:
         os.rmdir(config_dir)