I managed to get multiseat working with an gf6600gt and a s3 virge. But I get corrupted screen on geforce 6600gt (blinking pixels):
I also got corrupted screen with s3 virge, but I fixed with:
Option "XVideo" "false"
Option "slow_edodram" "true"
If I leave Xorg running for half hour, it will stop doing this on nvidia screen too. What is wrong?
Edit: S3/Virge graphics is on PCI and geforce is on AGP slot.