I have a weird problem playing video files. I have a fairly new (a few years old) graphic card that should and has played up to 1080p video files without much a lot of trouble.

I seem to be having a weird issue where the video plays back fine if the window is below a certain size, but as soon as the windowsize increases, the picture freezes. The audio still plays.

Usually this is mitigated by killing som applications. Especially GTK (?) apps seem to cause this lag, like having a Nautilus window open usually triggers this error for me.

With hardware rendering I get the error regardless of application. I have tried enabling software rendering in VLC and that eliminates the problem (but I get other problems using software rendering, so I've avoided it).

I know this is pretty fuzzy, but I'm not sure how to approach this problem. Do you have any idea?

EDIT: Some more information. I have the correct and latest drivers installed. My graphics card is a Nvidia 7600 GT.