Crashing as well...
I run RH7.3 on a Athlon 900,Gigabyte GA-7DXR and a GeForce4 4200 card.
It crashes for me too. In general there are two behaviors that I notice since I replaced my voodoo card with the NVidia card (aside from faster screen savers):
1. The "interupt that won't quit" error: Basically I'm working in X happily as can be, and suddenly everything except the mouse pointer freezes, and the pointer moves very choppily. Mp3's will continue to play, but slowly at points. This indicates to me that somehow some kind of interrupt is stealing away my CPU as well as causing X to crash. Keyboard doesn't respond, although I have had success logging in remotely during this behavior to attempt a reboot. Unfortunately this problem invariably leads to problem #2 on such attemps:
2. The "no hope for recovery" error. Basically X locks terminally, the keyboard "num lock" and "caps lock" (i think, or it could be all three) flash on and off, and my system is dead to all input whatsoever. Generally these problems are more apt to occur when changing resolutions or starting X, although they've happened at all times of use.
Now sometimes I'm lucky enough to get #1 before I get #2, other times it skips right to #2. I've disabled almost every non-essential thing (com ports, etc) but this has not helped anything. Also, curiously, when I set my AGP port in BIOS to be "as slow as possible", These errors happen more regularly. When I set the AGP bus to be at full speed, they happen less frequently.
Just to give you an idea, I had my system running 8 days and now just 5 days before it happens. When I'm not at my system I'll switch to a virtual terminal to (hopefully) lessen the liklihood of a crash in my absence.
I'll try disabling all the power saving stuff I can to see if that helps.
Any ideas? Nvidia???