No, I have an MSI K8T Neo..Single cpu...just AMD-64 and not optetron. My video card is an 5700 Ultra. But it does the same thing with an ti4200 also.
I played around with different kernel config's to see if I could get it to work.
Like I said earlier Im using a 2.6.0 test-11 kernel with patches
1. Do Not select IOMMU in processor features.
2. Compile agpgart and amd64-agpgart into the kernel and not as modules.
3. After kernel recompile is done just do the normal compiles for the nvidia driver and glx driver. Do not use "Option "NvidiaAGP" "1" in xf86config..2 or 3 is ok but doesnt make any difference.
Thats how I got mine working. Hope this helps.
attached is my kernel config...