Sounds like you don't have proper permissions on ~/.config/gpodder/database.sqlite or the file is opened by someone else. Please check - maybe another gPodder instance is still running? Also, try to remove ~/.config/gpodder/ (backup any existing data in case you need it later) and start gPodder again.
~/.config $ rm -rf gpodder/ ~/.config $ gpodder --fremantle Error detecting libnotify server. Creating new from file gPodder Creating new from file gPodderEpisodes /usr/lib/python2.5/site-packages/gpodder/gtkui/base.py:64: GtkWarning: HildonStackableWindow does not have a property called padding self.builder.add_from_file(filename) /usr/lib/python2.5/site-packages/gpodder/gtkui/base.py:64: GtkWarning: HildonStackableWindow does not have a property called expand self.builder.add_from_file(filename) /usr/lib/python2.5/site-packages/gpodder/gtkui/base.py:64: GtkWarning: HildonStackableWindow does not have a property called fill self.builder.add_from_file(filename) Creating new from file gPodderPodcasts Creating new from file gPodderDownloads /usr/lib/python2.5/site-packages/gpodder/gui.py:640: GtkWarning: _gtk_tree_view_column_autosize: assertion `GTK_IS_TREE_VIEW (tree_view)' failed column.set_property('min-width', 150) /usr/lib/python2.5/site-packages/gpodder/gui.py:641: GtkWarning: _gtk_tree_view_column_autosize: assertion `GTK_IS_TREE_VIEW (tree_view)' failed column.set_property('max-width', 150) ~/.config $