Quake3 will react as you describe if you have set the cvars that force screen refresh rates, you should leave them unset (so they default).
seta r_swapInterval "0"
seta r_displayrefresh "0"
I've had minimal success locking r_displayrefresh to 85, but occasionally do see the excessively slow main menu operation you described. You might try deleting all the q3config.cfg files in the directories (including mods) to fully rebuild configs (save copies if you wish).
You haven't mentioned any output from glxgears, does this function (and how fast does it render)? I have a feeling you might have Mesa conflicts, which are resolved by removing the rpm 'XFree86-Mesa-libGL" before installing the nVidia driver (either by rpm or installer script).
"..the triumph of evil is for good men to do nothing."
VIDIA video driver RPMs for Fedora
:: see yum repo at livna.org