Jittery Videos

[Brechin]

Ok, so I have been watching a few different videos and when I maximize a video it will jitter a few times throughout the video.

Not sure what is causing this, I'm using a 9800GTX and XP

 

[Brechin]

Ok, so I've tried enabling and disabling Adobe Shockwave, I've looked at other videos than just the ones on youtube. All of which do the same thing. The video will be fully buffered and still it jitters. Does anyone have a trouble shooting link for this problem or at least some opinions on what to check and try and fix?