Well, I got the Radeon card (Radeon 7500 64 MB DDR with v/D/O) as a replacement for the GeForce. When I received it, I was dismayed to find that it was "Powered by ATi" rather than "Built by ATi". Apparently, support for the "Powered by" cards is inconsistent. The card manufacturer is Sapphire. As it turns out, the card installed with minimal difficulty and works flawlessly. I'm getting glxgears at its default screen size over a 1280x1024 24 bpp desktop to put out about 880 fps.
I've had the card up for about 72 h, now, and it appears to work flawlessly without lockup at 1x AGP (2x is still a bit of a problem.) The only difficulty I had in getting the card to run was resolved by removing the nVIDIA GLX stuff and replacing it with stock GLX.
Thanks to everyone for your consideration and for your help.
Last edited by dave; 01-09-03 at 08:34 AM.