I had the same problem with my normal TNT. The workaround I used is to edit the nv4.inf file in the TNT(2) driver download. It includes all the possible refresh rates for all nvidia cards at all resolutions and color depths. In the .inf, find the section with your card, then the line with the resolution and color depth you wish to use with quake. Edit out the refresh rates you don't wish to be able to use, replacing them with spaces. (Examples of how it should look are scattered around the file, such as a couple places where 60Hz isn't supported and the next highest is 70Hz.) Good luck getting it to work!
--Spectre