mplayer - green screen

I'm running SuSE 8.1. I'm trying to play some AVI movie files, which play flawlessly on my Media Player in Windows. If I try and open the files in Konqueror, the task list says Mplayer and I see the hourglass moving for about 30 seconds, then the Mplayer entry disappears and nothing happens. If I open a terminal and use the command "mplayer (filename)", the movie opens with a green screen; the audio works fine. I used Yast to reinstall the Mplayer package, but that did not correct the problem. Has anyone else had a similar experience? Please advise. Thanks. Vince