diff --git a/src/calibre/gui2/actions/choose_library.py b/src/calibre/gui2/actions/choose_library.py
index d726241432..001970f9db 100644
--- a/src/calibre/gui2/actions/choose_library.py
+++ b/src/calibre/gui2/actions/choose_library.py
@@ -390,7 +390,7 @@ class ChooseLibraryAction(InterfaceAction):
         #self.dbref = weakref.ref(self.gui.library_view.model().db)
         #self.before_mem = memory()/1024**2
         self.gui.library_moved(loc)
-        #QTimer.singleShot(1000, self.debug_leak)
+        #QTimer.singleShot(5000, self.debug_leak)
 
     def debug_leak(self):
         import gc
@@ -398,7 +398,7 @@ class ChooseLibraryAction(InterfaceAction):
         ref = self.dbref
         for i in xrange(3): gc.collect()
         if ref() is not None:
-            print 11111, ref()
+            print 'DB object alive:', ref()
             for r in gc.get_referrers(ref())[:10]:
                 print r
                 print
diff --git a/src/calibre/gui2/convert/look_and_feel.ui b/src/calibre/gui2/convert/look_and_feel.ui
index 0edc324dc5..3dea1f66d7 100644
--- a/src/calibre/gui2/convert/look_and_feel.ui
+++ b/src/calibre/gui2/convert/look_and_feel.ui
@@ -43,7 +43,7 @@
       <double>0.000000000000000</double>
      </property>
      <property name="maximum">
-      <double>30.000000000000000</double>
+      <double>50.000000000000000</double>
      </property>
      <property name="singleStep">
       <double>1.000000000000000</double>
diff --git a/src/calibre/gui2/dialogs/scheduler.py b/src/calibre/gui2/dialogs/scheduler.py
index 572bbcf1c4..8aa624cacc 100644
--- a/src/calibre/gui2/dialogs/scheduler.py
+++ b/src/calibre/gui2/dialogs/scheduler.py
@@ -250,22 +250,27 @@ class Scheduler(QObject):
 
         self.timer = QTimer(self)
         self.timer.start(int(self.INTERVAL * 60 * 1000))
-        self.oldest_timer = QTimer()
-        self.connect(self.oldest_timer, SIGNAL('timeout()'), self.oldest_check)
         self.connect(self.timer, SIGNAL('timeout()'), self.check)
         self.oldest = gconf['oldest_news']
-        self.oldest_timer.start(int(60 * 60 * 1000))
         QTimer.singleShot(5 * 1000, self.oldest_check)
         self.database_changed = self.recipe_model.database_changed
 
     def oldest_check(self):
         if self.oldest > 0:
             delta = timedelta(days=self.oldest)
-            ids = self.recipe_model.db.tags_older_than(_('News'), delta)
+            try:
+                ids = self.recipe_model.db.tags_older_than(_('News'), delta)
+            except:
+                # Should never happen
+                ids = []
+                import traceback
+                traceback.print_exc()
             if ids:
                 ids = list(ids)
                 if ids:
                     self.delete_old_news.emit(ids)
+        QTimer.singleShot(60 * 60 * 1000, self.oldest_check)
+
 
     def show_dialog(self, *args):
         self.lock.lock()
diff --git a/src/calibre/gui2/tag_view.py b/src/calibre/gui2/tag_view.py
index 5a57395530..2160e13b65 100644
--- a/src/calibre/gui2/tag_view.py
+++ b/src/calibre/gui2/tag_view.py
@@ -727,7 +727,11 @@ class TagsModel(QAbstractItemModel): # {{{
         for user_cat in sorted(self.db.prefs.get('user_categories', {}).keys(),
                                key=sort_key):
             cat_name = '@' + user_cat # add the '@' to avoid name collision
-            tb_cats.add_user_category(label=cat_name, name=user_cat)
+            try:
+                tb_cats.add_user_category(label=cat_name, name=user_cat)
+            except ValueError:
+                import traceback
+                traceback.print_exc()
         if len(saved_searches().names()):
             tb_cats.add_search_category(label='search', name=_('Searches'))
 
diff --git a/src/calibre/library/caches.py b/src/calibre/library/caches.py
index 7d6511e8a5..af47a79e49 100644
--- a/src/calibre/library/caches.py
+++ b/src/calibre/library/caches.py
@@ -42,7 +42,8 @@ class MetadataBackup(Thread): # {{{
 
     def stop(self):
         self.keep_running = False
-        self.flush()
+
+    def break_cycles(self):
         # Break cycles so that this object doesn't hold references to db
         self.do_write = self.get_metadata_for_dump = self.clear_dirtied = \
             self.set_dirtied = self.db = None
@@ -111,6 +112,8 @@ class MetadataBackup(Thread): # {{{
                     continue
 
             self.in_limbo = None
+        self.flush()
+        self.break_cycles()
 
     def flush(self):
         'Used during shutdown to ensure that a dirtied book is not missed'
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index f2b2c94e31..ed47abbdb3 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -1376,10 +1376,12 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
     def tags_older_than(self, tag, delta):
         tag = tag.lower().strip()
         now = nowf()
+        tindex = self.FIELD_MAP['timestamp']
+        gindex = self.FIELD_MAP['tags']
         for r in self.data._data:
             if r is not None:
-                if (now - r[self.FIELD_MAP['timestamp']]) > delta:
-                    tags = r[self.FIELD_MAP['tags']]
+                if (now - r[tindex]) > delta:
+                    tags = r[gindex]
                     if tags and tag in [x.strip() for x in
                             tags.lower().split(',')]:
                         yield r[self.FIELD_MAP['id']]
diff --git a/src/calibre/library/field_metadata.py b/src/calibre/library/field_metadata.py
index cfd95b2e3c..902e43891c 100644
--- a/src/calibre/library/field_metadata.py
+++ b/src/calibre/library/field_metadata.py
@@ -479,6 +479,8 @@ class FieldMetadata(dict):
                 del self._tb_cats[key]
                 if key in self._search_term_map:
                     del self._search_term_map[key]
+                if key.lower() in self._search_term_map:
+                    del self._search_term_map[key.lower()]
 
     def cc_series_index_column_for(self, key):
         return self._tb_cats[key]['rec_index'] + 1