I'm a happy Amarok user, using it for playing/browsing/querying my music collection, but this weekend I encountered a problem: Amarok didn't start anymore. When I launched Amarok (version 1.3.1, that is) from the command line I got the following error:
$> amarok amaroK: [Loader] Starting amarokapp.. amaroK: [Loader] Don't run gdb, valgrind, etc. against this binary! Use amarokapp. QLayout: Adding KToolBar/mainToolBar (child of QVBox/unnamed) to layout for PlaylistWindow/PlaylistWindow kio (Scheduler): FATAL: BUG! _ScheduleJob(): No extraJobData for job!
I experimented with changing/deleting my Amarok settings in ~/.kde/share/apps/amarok and it became clear that there was some problem with collection.db. Deleting (after a backup of course) that file would solve the problem, but I did not want to lose the statistical information about my music collection in that file.