diff --git a/src/calibre/gui2/ui.py b/src/calibre/gui2/ui.py
index 2082a3b90a..cc2975e7a7 100644
--- a/src/calibre/gui2/ui.py
+++ b/src/calibre/gui2/ui.py
@@ -565,9 +565,6 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, # {{{
         mb = self.library_view.model().metadata_backup
         if mb is not None:
             mb.stop()
-            # give the thread time to stop so all operations complete
-            # otherwise the exit could kill the thread mid-write
-            time.sleep(2)
 
         self.hide_windows()
         self.emailer.stop()
@@ -579,9 +576,9 @@ class Main(MainWindow, MainWindowMixin, DeviceMixin, # {{{
                     s.exit()
             except:
                 pass
-            time.sleep(2)
         except KeyboardInterrupt:
             pass
+        time.sleep(2)
         self.hide_windows()
         return True
 
diff --git a/src/calibre/library/database2.py b/src/calibre/library/database2.py
index a9d372bed1..192de21df3 100644
--- a/src/calibre/library/database2.py
+++ b/src/calibre/library/database2.py
@@ -573,8 +573,6 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         The last step is clearing the indicator
         '''
         for book_id in book_ids:
-            if not self.data.has_id(book_id):
-                continue
             self.conn.execute('DELETE FROM metadata_dirtied WHERE book=?',
                     (book_id,))
             # if a later exception prevents the commit, then the dirtied
@@ -588,9 +586,6 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
             commit=True):
         '''
         Write metadata for each record to an individual OPF file
-
-        :param dump_to: None or list. If list then instead of writing to file,
-                        data is append to list
         '''
         if book_ids is None:
             book_ids = [x[0] for x in self.conn.get(
@@ -611,7 +606,6 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
                 self.dirtied([book_id])
         if commit:
             self.conn.commit()
-        return True
 
     def dirtied(self, book_ids, commit=True):
         for book in book_ids:
@@ -657,7 +651,7 @@ class LibraryDatabase2(LibraryDatabase, SchemaUpgrade, CustomColumns):
         except:
             # This almost certainly means that the book has been deleted while
             # the backup operation sat in the queue.
-            path,mi = (None, None)
+            path, mi = (None, None)
 
         try:
             # clear the dirtied indicator. The user must put it back if