I've found that an Alt-SysRq-k (kill all processes on current virtual console) is a much safer way to restart X after this error occurs. Certainly safer than pulling the power.
I have this exact issue on a system running:
(II) Loading /usr/lib/xorg/modules/drivers//i810_drv.so
(II) Module i810: vendor="X.Org Foundation"
compiled for 1.4.0, module version = 2.2.0
Module class: X.Org Video Driver
ABI class: X.Org Video Driver, version 2.0
Time to attempt a rollback, I think.
Martin
