Video on board problem

[ron2368]

I have a ecsp4800mpro that has onboard video. When I play a video in media player the screen intermittently flickers. I have tried lowering hardware acceleration , it does not help. There are two memory settings in the bios graphics share memory and aperature size select. I have set both to high amounts but no change. Upgraded the driver but same problem. My monitor setting are well within the video chips specs like refresh and resolution. any ideas appreciated. thanks