diff --git a/cps/db.py b/cps/db.py
index a5a01aca..40ba1753 100644
--- a/cps/db.py
+++ b/cps/db.py
@@ -48,6 +48,7 @@ try:
 except ImportError:
     use_unidecode = False
 
+Session = None
 
 cc_exceptions = ['datetime', 'comments', 'composite', 'series']
 cc_classes = {}
@@ -409,6 +410,7 @@ class CalibreDB():
     def setup_db(self, config, app_db_path):
         self.config = config
         self.dispose()
+        global Session
 
         if not config.config_calibre_dir:
             config.invalidate()
@@ -506,7 +508,7 @@ class CalibreDB():
                                          backref='books'))
 
         Session = scoped_session(sessionmaker(autocommit=False,
-                                              autoflush=False,
+                                              autoflush=True,
                                               bind=self.engine))
         self.session = Session()
         return True
diff --git a/cps/tasks/convert.py b/cps/tasks/convert.py
index a9cbfbd2..2b679fc0 100644
--- a/cps/tasks/convert.py
+++ b/cps/tasks/convert.py
@@ -53,6 +53,7 @@ class TaskConvert(CalibreTask):
 
     def _convert_ebook_format(self):
         error_message = None
+        local_session = db.Session()
         file_path = self.file_path
         book_id = self.bookid
         format_old_ext = u'.' + self.settings['old_book_format'].lower()
@@ -92,17 +93,13 @@ class TaskConvert(CalibreTask):
                 new_format = db.Data(name=cur_book.data[0].name,
                                          book_format=self.settings['new_book_format'].upper(),
                                          book=book_id, uncompressed_size=os.path.getsize(file_path + format_new_ext))
-
-                cur_book.data.append(new_format)
-
                 try:
-                    # db.session.merge(cur_book)
-                    calibre_db.session.commit()
+                    local_session.merge(new_format)
+                    local_session.commit()
                 except SQLAlchemyError as e:
-                    calibre_db.session.rollback()
+                    local_session.rollback()
                     log.error("Database error: %s", e)
                     return
-
                 self.results['path'] = cur_book.path
                 self.results['title'] = cur_book.title
                 if config.config_use_google_drive: