As far as I can tell, the problem is really similar to this *closed* bug: https://bugs.maemo.org/show_bug.cgi?id=6823
I've tried a lot of things (restarting trackerd, killing mafw-*, reboots, run it with strace, etc.) without success. When trying to play any audio/video file, it still shows this error message (translated from french) "impossible to process operation", even trying to change the mediaplayer volume triggers this error. (...) Note: openmediaplayer suffers of the same problems, an was working good when mediaplayer was working too.