Video streams playback problem!

[pandaking]

OK, here is my problem:

When I try and stream videos, some work fine (although constant re-buffering (due to my internet connection?), whilst others cause this odd little problem. With these one, I get sound, but the video is all really bright colours, mostly purple and like big squares of it on the screen. You can kind of see the image at points and then after a few seconds of this winamp just closes.

Is this due to some missing codecs or something? Any help is greatly appreciated.

Info on my system are in my sig. Don't think my computer specs will be of much use, it's all good stuff, if you need specs just say.

Anything else you need please also say as well