I've got a PNY Geforce 2 MX PCI card that has a jittery display. Other than
the jitter, the picture is fine. It only jitters horizontally. The picture
is stable vertically. I was just wondering if anyone could suggest what
might be causing it?

In text modes (BIOS screen, etc.) you barely notice any jitter. At higher
resolutions the jitter becomes more apparent. At 60hz it's more of a wave,
with the left and right edges of the screen looking like small crescent
shapes. At 85Hz it's just a random jitter.

Power is coming from an Antec 380watt PSU and the display is fine with an
AGP ATI Radeon 9600XT, so I don't think there is a problem with the power
feeding the card.

I'm hoping it's just something like a filter capacitor or something similar.

I'll try and post a picture of the screen and card when I get a chance...

Any suggestions on what to look for?