Is it because I have to many different video-players installed ?
after update from 12.04 to 12.10 it seems, that video-playing is not working any more ? it crashes, or ends up with "we have found a system-failure" - window. (failure-report is not working and crashing too after correct password).
this concerns: medibuntu, mediaplayer, totem, mplayer and xine (probably too many installed and I should decide for only one ? - but it was no problem in 12.04 ?).