WEIRD OpenGL problems

I'm not sure if this is the right place to post, but I guess it's a start:

Setup:

FIC-SD11 Mainboard
Athlon 600
Geforce 256 DDR, by Elsa (Erazor X2)
Windows 98
256 MB SDRAM/100Mhz

I started having this problem recently where nothing using OpenGl works; a game like Counterstrike will run for about 30 seconds, then the whole system freezes. Usually it will page fault with NVOPENGL.DLL or somesuch. There was no clear point at which the problem started, except that I recently brought my box into the office so I could download some stuff, at which point I reinstalled my old SMC network card, which uses my only ISA slot.

I have reinstalled Geforce drivers several different ways, and they are the latest as far as I can tell. I have reverted back to the original manufacturer's drivers, I have reinstalled Windows 98. Nothing seems to make a difference. I tried GLsetup, which just told me that my drivers were more recent than the ones it had. I have DirectX 8.0. I have changed my AGP Aperture Size to every possible setting, but nothing makes any difference. I have done most everything possible on geforcefaq.com. I do not have IRQ conflicts, etc, and I have swapped my SCSI adapter from PCI slot 0 to the last one.

Again, the only things that changed were that I moved the physical location of the machine, and I added a network card. How the hell could this screwup OpenGl functionality? I can play CS in software mode just fine, but it sucks and it's slow. Every other game that uses OpenGl has the same problem. It's clearly something with openGL.

One thing I noticed on my motherboard manufacturer's website (FIC) is that cards such as the Geforce 256 do not run on it. Yet, I have been using this setup since May of last year! So even though I'd like to go through all the hassle of buying a new motherboard just to see if OpenGl will work, I doubt it's the problem. HELP!