Huh:
for d3d-games you have to set resolution to ++max.++ 1024*768, for ogl-games you must set resolution to ++min.++ 1280*960 (16 bit colordepth)
This article in alt.games.quake3 says the same. This (non-Usenet) article among others say you have to convince the GeForce card it's a Quadro, but they all (I think) predate these Detonator XP drivers we're using.