No image in media player, HTPC with NX7600GT & Pioneer PDP506

Hi

I cant get my HTPC to work. I get sound, but no image.

PC with MSI NX7600GT (hdmi out)
Windows XP, tried Windows media player, zplayer and VLC.
Pioneer PDP506 plasma connected via HDMI.

The television detects 750p, not 720p av the computer say. Strange?

Got it to work for a while when I was using VMR9 as video render, but the image was a bit defect. Horisontal lines appeared while playing...

Is there anyone who can help? Please..

ok, tried another card. A NX8600GTS, it works perfectly!

So, avoid the nx7600GT ...