Same problem - system freeze (VIA chipset)
I have the same problem RH8 and kernel 2.4.8-18 and a new VIA chipset with AGP8 support (That is why I bought this).
When I start X the system freezes still in text mode with random characters all over - I cannot event telnet/ssh to the system after this I have to do a hard reboot.
Every thing looks fine in the XFree log even with debug level 5 nothing seems wrong.
I am sure I am using the right RPMs for my kernel, and I am sure that my XConfig is also rightt removed the "GLcore" and also "glx" and changed driver to "nvidia"..
It looks like there is a problem with VIA chipset and all/some GForce cards..
I have a TI-42000 (with AGP8 support).