can't stream video in full screen from internet

Hi folks;

I was wondering if someone on this forum could help answer this question.

I recently built a new PC. Here are my specs.

Gigabyte P55-UD3 mobo

GSkill 2x2Gb 1333 MHz DDR3

Radeon 5770 1 GB

Intel Core i5 Quad 2.66 GHz

Win XP SP3

After installing the h/w I downloaded all the latest drivers for the BIOS, GPU, etc from the OEM websites. I seem to have everything working correctly except for one thing. If I try to stream tv from my internet browser I cannot do so in full screen. Default screen size plays fine but when I click to go full screen the audio plays ok but the screen freezes after about 3 seconds. Nothing else appears to be frozen and I can jump back to small screen at any time. Some websites will stream fine after jumping in and out of full screen once, others will not play full screen at all. I tested this in Firefox and IE7 and both show the same symptoms; however, iTunes plays video full screen just fine.

I uninstalled Adobe Flash Player and upgraded to 10.0.42.34 but the problem persists. I can't see anything in the Catalyst control center that would affect this (pretty much everything there is set to auto and none of my games show any frame rate issues). Any advice would be appreciated.

thanks,