[Lilux-help] Problems with playing video files

Hello, I have trouble with output of video files (.mpg, playing DVDs, etc) in my new installation. Before installing the sound-card, I could watch mpgs in kaffeine or xine. After installing the sound card, I have permanent crashes of both applications. In KDE, they crash before playing anything, in IceWM, the kaffeine plays the sound, but not the video of mpg files. Error messages are the following: (on the console:) kaffeine: simple.c:1513: snd_mixer_selem_set_playback_volume: Assertion `elem->type == SND_MIXER_ELEM_SIMPLE' failed. ERROR: Communication problem with kaffeine, it probably crashed. (in the KDE Crash Handler:) (no debugging symbols found)...Using host libthread_db library "/lib/tls/libthread_db.so.1". (...) #4 0x412ebe8b in __waitpid_nocancel () from /lib/tls/libpthread.so.0 #5 0x40881f32 in KCrash::defaultCrashHandler () from /opt/kde3/lib/libkdecore.so.4 #6 <signal handler called> #7 0xffffe410 in ?? () #8 0xbfffdb4c in ?? () #9 0x00000006 in ?? () #10 0x00002a50 in ?? () #11 0x414527a1 in raise () from /lib/tls/libc.so.6 #12 0x41453f79 in abort () from /lib/tls/libc.so.6 #13 0x4144bfe3 in __assert_fail () from /lib/tls/libc.so.6 #14 0x418e4b15 in snd_mixer_selem_set_playback_volume () from /usr/lib/libasound.so.2 #15 0x42744443 in ao_alsa_set_property () from /usr/lib/xine/plugins/1.0.0/xineplug_ao_out_alsa.so #16 0x08343ef0 in ?? () #17 0x00000000 in ?? () #18 0x00000000 in ?? () #19 0xbfffdd10 in ?? () #20 0x4147b3fb in sscanf () from /lib/tls/libc.so.6 Does anybody have an idea how I can fix this problem ?? Thanks for your help JJ Mouris