Nvidia Windows vista DVI to HDMI Problem!!

[goonies]

I have an Nvidia Geforce 7800 GT Graphic card working in Windows Vista. When I am playing back a video with the DVI Connect to my Sony HDTV with HDMI I get a line going across the screen sometimes when there is a fast change of picture. But when I change the Screen resolution on my P.C. Monitor to 800x600 it seems to stop. But when I change it back to 1024x768 the problem is still there! Do I need a graphic card with more Memory? My graphic card has 256 already!

 

[Tetrahedron]

what model Sony HDTV do you have? Have your also tried a DVI to VGA adapter and then hooking up the PC through a VGA cable to the TV and see if you get the same results?

 

[goonies]

I have a Sony Bravia KDL-V32A12U. I can't hook it up to a VGA Adaptor because I only have HDMI and Component on my T.V. But I do have the converter from DVI TO VGA To my monitor?