diff --git a/src/calibre/devices/interface.py b/src/calibre/devices/interface.py
index 6247e29e15..b38b62e20c 100644
--- a/src/calibre/devices/interface.py
+++ b/src/calibre/devices/interface.py
@@ -402,17 +402,3 @@ class BookList(list):
         '''
         raise NotImplementedError()
 
-    def add_book(self, book, collections=None):
-        '''
-        Add the book to the booklist. Intent is to maintain any device-internal
-        metadata
-        '''
-        if book not in self:
-            self.append(book)
-
-    def remove_book(self, book):
-        '''
-        Remove a book from the booklist. Correct any device metadata at the
-        same time
-        '''
-        self.remove(book)
diff --git a/src/calibre/devices/prs505/books.py b/src/calibre/devices/prs505/books.py
index ba3605530e..855d8d5cd3 100644
--- a/src/calibre/devices/prs505/books.py
+++ b/src/calibre/devices/prs505/books.py
@@ -8,7 +8,7 @@ import xml.dom.minidom as dom
 from base64 import b64encode as encode
 
 
-from calibre.devices.interface import BookList as _BookList
+from calibre.devices.usbms.books import BookList as _BookList
 from calibre.devices import strftime as _strftime
 from calibre.devices.usbms.books import Book as _Book
 from calibre.devices.prs505 import MEDIA_XML
@@ -31,36 +31,6 @@ def uuid():
 def sortable_title(title):
     return re.sub('^\s*A\s+|^\s*The\s+|^\s*An\s+', '', title).rstrip()
 
-class book_metadata_field(object):
-    """ Represents metadata stored as an attribute """
-    def __init__(self, attr, formatter=None, setter=None):
-        self.attr = attr
-        self.formatter = formatter
-        self.setter = setter
-
-    def __get__(self, obj, typ=None):
-        """ Return a string. String may be empty if self.attr is absent """
-        return self.formatter(obj.elem.getAttribute(self.attr)) if \
-                           self.formatter else obj.elem.getAttribute(self.attr).strip()
-
-    def __set__(self, obj, val):
-        """ Set the attribute """
-        val = self.setter(val) if self.setter else val
-        if not isinstance(val, unicode):
-            val = unicode(val, 'utf8', 'replace')
-        obj.elem.setAttribute(self.attr, val)
-
-
-class Book(_Book):
-    @dynamic_property
-    def db_id(self):
-        doc = '''The database id in the application database that this file corresponds to'''
-        def fget(self):
-            match = re.search(r'_(\d+)$', self.rpath.rpartition('.')[0])
-            if match:
-                return int(match.group(1))
-        return property(fget=fget, doc=doc)
-
 class BookList(_BookList):
 
     def __init__(self, oncard, prefix):
@@ -318,7 +288,12 @@ class BookList(_BookList):
             imap = {}
             for book, sony_id in zip(books, sony_ids):
                 if book is not None:
-                    imap[book.application_id] = sony_id
+                    db_id = book.application_id
+                    if db_id is None:
+                        db_id = book.db_id
+                        print 'here', db_id
+                    if db_id is not None:
+                        imap[book.application_id] = sony_id
             # filter the list, removing books not on device but on playlist
             books = [i for i in books if i is not None]
             # filter the order specification to the books we have
diff --git a/src/calibre/devices/prs505/driver.py b/src/calibre/devices/prs505/driver.py
index 0b41894a18..1d403cb75d 100644
--- a/src/calibre/devices/prs505/driver.py
+++ b/src/calibre/devices/prs505/driver.py
@@ -13,6 +13,7 @@ import os
 import re
 
 from calibre.devices.usbms.driver import USBMS
+from calibre.devices.usbms.books import Book
 from calibre.devices.prs505.books import BookList, fix_ids
 from calibre.devices.prs505 import MEDIA_XML
 from calibre.devices.prs505 import CACHE_XML
@@ -59,8 +60,9 @@ class PRS505(USBMS):
     METADATA_CACHE = "database/cache/metadata.calibre"
 
     def initialize(self):
-        USBMS.initialize(self)
+        USBMS.initialize(self) # Must be first, so _class vars are set right
         self.booklist_class = BookList
+        self.book_class = Book
 
     def windows_filter_pnp_id(self, pnp_id):
         return '_LAUNCHER' in pnp_id
diff --git a/src/calibre/devices/usbms/books.py b/src/calibre/devices/usbms/books.py
index bc6003de27..ce74db6f54 100644
--- a/src/calibre/devices/usbms/books.py
+++ b/src/calibre/devices/usbms/books.py
@@ -37,12 +37,8 @@ class Book(MetaInformation):
         else:
             self.lpath = lpath
         self.mime = mime_type_ext(path_to_ext(lpath))
-        self.size = os.stat(self.path).st_size if size == None else size
-        self.db_id = None
-        try:
-            self.datetime = time.gmtime(os.path.getctime(self.path))
-        except ValueError:
-            self.datetime = time.gmtime()
+        self.size = None # will be set later
+        self.datetime = time.gmtime()
 
         if other:
             self.smart_update(other)
@@ -70,6 +66,16 @@ class Book(MetaInformation):
 
         return spath == opath
 
+    @dynamic_property
+    def db_id(self):
+        doc = '''The database id in the application database that this file corresponds to'''
+        def fget(self):
+            match = re.search(r'_(\d+)$', self.lpath.rpartition('.')[0])
+            if match:
+                return int(match.group(1))
+            return None
+        return property(fget=fget, doc=doc)
+
     @dynamic_property
     def title_sorter(self):
         doc = '''String to sort the title. If absent, title is returned'''
@@ -81,13 +87,6 @@ class Book(MetaInformation):
     def thumbnail(self):
         return None
 
-#    def __str__(self):
-#        '''
-#        Return a utf-8 encoded string with title author and path information
-#        '''
-#        return self.title.encode('utf-8') + " by " + \
-#               self.authors.encode('utf-8') + " at " + self.path.encode('utf-8')
-
     def smart_update(self, other):
         '''
         Merge the information in C{other} into self. In case of conflicts, the information
@@ -115,3 +114,17 @@ class BookList(_BookList):
     def set_tags(self, book, tags):
         book.tags = tags
 
+    def add_book(self, book, collections=None):
+        '''
+        Add the book to the booklist. Intent is to maintain any device-internal
+        metadata
+        '''
+        if book not in self:
+            self.append(book)
+
+    def remove_book(self, book):
+        '''
+        Remove a book from the booklist. Correct any device metadata at the
+        same time
+        '''
+        self.remove(book)
diff --git a/src/calibre/devices/usbms/driver.py b/src/calibre/devices/usbms/driver.py
index 1a5b7461ed..361f7ea1bf 100644
--- a/src/calibre/devices/usbms/driver.py
+++ b/src/calibre/devices/usbms/driver.py
@@ -34,6 +34,7 @@ class USBMS(CLI, Device):
     def initialize(self):
         Device.initialize(self)
         self.booklist_class = BookList
+        self.book_class = Book
 
     def get_device_information(self, end_session=True):
         self.report_progress(1.0, _('Get device information...'))
@@ -52,7 +53,9 @@ class USBMS(CLI, Device):
             self.report_progress(1.0, _('Getting list of books on device...'))
             return []
 
-        prefix = self._card_a_prefix if oncard == 'carda' else self._card_b_prefix if oncard == 'cardb' else self._main_prefix
+        prefix = self._card_a_prefix if oncard == 'carda' else \
+                                     self._card_b_prefix if oncard == 'cardb' \
+                                                         else self._main_prefix
         metadata = self.booklist_class(oncard, prefix)
 
         ebook_dirs = self.EBOOK_DIR_CARD_A if oncard == 'carda' else \
@@ -61,7 +64,6 @@ class USBMS(CLI, Device):
 
         bl, need_sync = self.parse_metadata_cache(prefix, self.METADATA_CACHE,
                                                   self.booklist_class(oncard, prefix))
-
         # make a dict cache of paths so the lookup in the loop below is faster.
         bl_cache = {}
         for idx,b in enumerate(bl):
@@ -77,10 +79,10 @@ class USBMS(CLI, Device):
                         lpath = lpath[len(os.sep):]
                     idx = bl_cache.get(lpath.replace('\\', '/'), None)
                     if idx is not None:
-                        item, changed = self.__class__.update_metadata_item(bl[idx])
+                        item, changed = self.update_metadata_item(bl[idx])
                         self.count_found_in_bl += 1
                     else:
-                        item = self.__class__.book_from_path(prefix, lpath)
+                        item = self.book_from_path(prefix, lpath)
                         changed = True
                     metadata.append(item)
                 except: # Probably a filename encoding error
@@ -175,7 +177,10 @@ class USBMS(CLI, Device):
             lpath = path.partition(prefix)[2]
             if lpath.startswith(os.sep):
                 lpath = lpath[len(os.sep):]
-            book = Book(prefix, lpath, other=info)
+            book = self.book_class(prefix, lpath, other=info)
+            if book.size is None:
+                book.size = os.stat(path).st_size
+
             opts = self.settings()
             collections = opts.extra_customization.split(',') if opts.extra_customization else []
             booklists[blist].add_book(book, collections, *location[1:-1])
@@ -229,19 +234,14 @@ class USBMS(CLI, Device):
 
         self.report_progress(1.0, _('Sending metadata to device...'))
 
-    @classmethod
-    def parse_metadata_cache(cls, prefix, name, bl):
+    def parse_metadata_cache(self, prefix, name, bl):
         js = []
         need_sync = False
         try:
             with open(os.path.join(prefix, name), 'rb') as f:
                 js = json.load(f, encoding='utf-8')
             for item in js:
-                lpath = item.get('lpath', None)
-                if not lpath or not os.path.exists(os.path.join(prefix, lpath)):
-                    need_sync = True
-                    continue
-                book = Book(prefix, lpath)
+                book = self.book_class(prefix, item.get('lpath', None))
                 for key in item.keys():
                     setattr(book, key, item[key])
                 bl.append(book)
@@ -249,35 +249,33 @@ class USBMS(CLI, Device):
             import traceback
             traceback.print_exc()
             bl = []
+            need_sync = True
         return bl, need_sync
 
-    @classmethod
-    def update_metadata_item(cls, item):
+    def update_metadata_item(self, item):
         changed = False
         size = os.stat(item.path).st_size
         if size != item.size:
             changed = True
-            mi = cls.metadata_from_path(item.path)
+            mi = self.metadata_from_path(item.path)
             item.smart_update(mi)
+            item.size = size
         return item, changed
 
-    @classmethod
-    def metadata_from_path(cls, path):
-        return cls.metadata_from_formats([path])
+    def metadata_from_path(self, path):
+        return self.metadata_from_formats([path])
 
-    @classmethod
-    def metadata_from_formats(cls, fmts):
+    def metadata_from_formats(self, fmts):
         from calibre.ebooks.metadata.meta import metadata_from_formats
         from calibre.customize.ui import quick_metadata
         with quick_metadata:
             return metadata_from_formats(fmts)
 
-    @classmethod
-    def book_from_path(cls, prefix, path):
+    def book_from_path(self, prefix, path):
         from calibre.ebooks.metadata import MetaInformation
 
-        if cls.settings().read_metadata or cls.MUST_READ_METADATA:
-            mi = cls.metadata_from_path(os.path.join(prefix, path))
+        if self.settings().read_metadata or self.MUST_READ_METADATA:
+            mi = self.metadata_from_path(os.path.join(prefix, path))
         else:
             from calibre.ebooks.metadata.meta import metadata_from_filename
             mi = metadata_from_filename(os.path.basename(path),
@@ -286,6 +284,6 @@ class USBMS(CLI, Device):
         if mi is None:
             mi = MetaInformation(os.path.splitext(os.path.basename(path))[0],
                     [_('Unknown')])
-
-        book = Book(prefix, path, other=mi)
+        mi.size = os.stat(os.path.join(prefix, path)).st_size
+        book = self.book_class(prefix, path, other=mi)
         return book
diff --git a/src/calibre/gui2/device.py b/src/calibre/gui2/device.py
index 828756e2c8..a9f69bbca5 100644
--- a/src/calibre/gui2/device.py
+++ b/src/calibre/gui2/device.py
@@ -523,7 +523,8 @@ class DeviceGUI(object):
             d = ChooseFormatDialog(self, _('Choose format to send to device'),
                                 self.device_manager.device.settings().format_map)
             d.exec_()
-            fmt = d.format().lower()
+            if d.format():
+                fmt = d.format().lower()
         dest, sub_dest = dest.split(':')
         if dest in ('main', 'carda', 'cardb'):
             if not self.device_connected or not self.device_manager:
@@ -998,7 +999,7 @@ class DeviceGUI(object):
             if changed:
                 self.library_view.model().refresh_ids(list(changed))
 
-    def book_on_device(self, index, format=None, reset=False):
+    def book_on_device(self, id, format=None, reset=False):
         loc = [None, None, None]
 
         if reset:
@@ -1030,7 +1031,7 @@ class DeviceGUI(object):
                     if uuid is not None:
                         self.book_db_uuid_cache[i].add(uuid)
 
-        mi = self.library_view.model().db.get_metadata(index, index_is_id=True)
+        mi = self.library_view.model().db.get_metadata(id, index_is_id=True)
         for i, l in enumerate(self.booklists()):
             if mi.uuid in self.book_db_uuid_cache[i]:
                 loc[i] = True
@@ -1038,7 +1039,7 @@ class DeviceGUI(object):
             db_title = re.sub('(?u)\W|[_]', '', mi.title.lower())
             cache = self.book_db_title_cache[i].get(db_title, None)
             if cache:
-                if index in cache['db_ids']:
+                if id in cache['db_ids']:
                     loc[i] = True
                     break
                 if mi.authors and \
@@ -1057,11 +1058,11 @@ class DeviceGUI(object):
                 mi = self.library_view.model().db.get_metadata(idx, index_is_id=False)
                 title = re.sub('(?u)\W|[_]', '', mi.title.lower())
                 if title not in self.db_book_title_cache:
-                    self.db_book_title_cache[title] = {'authors':set(), 'db_ids':set()}
+                    self.db_book_title_cache[title] = {'authors':{}, 'db_ids':{}}
                 authors = authors_to_string(mi.authors).lower() if mi.authors else ''
                 authors = re.sub('(?u)\W|[_]', '', authors)
-                self.db_book_title_cache[title]['authors'].add(authors)
-                self.db_book_title_cache[title]['db_ids'].add(mi.application_id)
+                self.db_book_title_cache[title]['authors'][authors] = mi
+                self.db_book_title_cache[title]['db_ids'][mi.application_id] = mi
                 self.db_book_uuid_cache.add(mi.uuid)
 
         # Now iterate through all the books on the device, setting the in_library field
@@ -1069,6 +1070,7 @@ class DeviceGUI(object):
         # is really the db key, but as this can accidentally match across libraries we
         # also verify the title. The db_id exists on Sony devices. Fallback is title
         # and author match
+        resend_metadata = False
         for booklist in booklists:
             for book in booklist:
                 if getattr(book, 'uuid', None) in self.db_book_uuid_cache:
@@ -1082,11 +1084,20 @@ class DeviceGUI(object):
                 if d is not None:
                     if getattr(book, 'application_id', None) in d['db_ids']:
                         book.in_library = True
+                        book.smart_update(d['db_ids'][book.application_id])
+                        resend_metadata = True
                         continue
                     if book.db_id in d['db_ids']:
                         book.in_library = True
+                        book.smart_update(d['db_ids'][book.db_id])
+                        resend_metadata = True
                         continue
                     book_authors = authors_to_string(book.authors).lower() if book.authors else ''
                     book_authors = re.sub('(?u)\W|[_]', '', book_authors)
                     if book_authors in d['authors']:
                         book.in_library = True
+                        book.smart_update(d['authors'][book_authors])
+                        resend_metadata = True
+        if resend_metadata:
+            # Correcting metadata cache on device.
+            self.device_manager.sync_booklists(None, booklists)
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index fd59503eed..b0f2d3cb39 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -470,14 +470,14 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             im = PILImage.open(f)
             im.convert('RGB').save(path, 'JPEG')
 
-    def book_on_device(self, index):
+    def book_on_device(self, id):
         if callable(self.book_on_device_func):
-            return self.book_on_device_func(index)
+            return self.book_on_device_func(id)
         return None
 
-    def book_on_device_string(self, index):
+    def book_on_device_string(self, id):
         loc = []
-        on = self.book_on_device(index)
+        on = self.book_on_device(id)
         if on is not None:
             m, a, b = on
             if m is not None: