I have a few video clips coded in XVID codec .. either 1) they show in one corner of the screen (size decreases), dock in the corner (even when it's full screen .. it only occupies 2/3 of the screen and in the corner) ... or 2) it plays a little and then the music/audio continues but the video screen freezes and eventually it crashes (sometimes) ...

Pls help ... what happened? and what should I do to resolve this problem?

thanks .. much much appreciate.

ps. I also have most of the codec downloaded