nVidia with stock kernel crashes when leaving X

[Chris]

I'm curious to know if anyone else has seen this or knows of a fix.  The 
nVidia forums were absolutely no help.

My system is an Opteron running an nVidia 250 Pro chipset motherboard 
and nVidia Geforce 5700 Ultra AGP video card.

When running the stock Ubuntu kernel (Breezy 2.6.12-9) and the nVidia 
binary drivers ("nvidia") everything works fine until I try to quit X11. 
  If I press CTRL-ALT-Fx, log-out, reboot, or absolutely anything that 
tries to leave X then the machine just dies.  I get a black screen and I 
can hear the video card actually power off (the fan stops running).  The 
system is then completely dead.  This happens in both Breezy 386 and 
AMD64 versions and it doesn't matter if I use the Ubuntu nVidia driver 
from restricted modules or compile my own.

This _only_ happens with the stock Ubuntu kernel.  If I build my own 
kernel the problem goes completely away.  The problem is that I want to 
run the stock kernel because I have not been able to build my own kernel 
that has working USB in VMware (for some reason only the stock kernel 
works with USB and VMware).

Thanks for any help.

-- 
// Chris