Macbook Screen Flickering in XP

[Storrow]

I just booted into Windows which is installed onto my Macbook CD via bootcamp. I noticed the screen brightness was flickering up and down as if someone was hitting the brightness up/down keys kind of rapidly. I'm not booted back into Mac OS and it doesnt seem to be doing it. My main concern is if this is my computer thats messed or or its just Windows XP.

Thanks very much for an thoughts on this.

 

[Shadow]

Refresh rate?