What a saga :-)
I went through hell with this, with RHL 7.2 I and
the 2880 it was ok with my dual athlon on a Tyan
S2462. Upograde to RHL 7.3 and 2.4.18-3,4,5 it was hosed. But I am now on 2.4.18-10 kernel and I seem to be ok. I never could make it through one round of Tuxracer before. Time permitting I will dig into this some more, it definelty seems to be a big performance hit with any of the open gl stuff going. ANyway, great thread with a great link.