I would stick with DVI for 3D, it doesnt limit the FPS, where as an HDMI can and most likely will limit your FPS... a buddy of mine did that, his FPS never went above 24 with HDMI but hit 60+ with DVI..... but that was with Radeon not Nvidia.
Most TVs don't got DVI connections....
and it seems that either:
the cable is faulty
the card is faulty
try a different cable... it should cost like $3 for a 5 foot cable...