Do you have laptop?
If not, i would disable power management..... (might help, might not)
Even if you have laptop, try disabling power management.
As far as i know, there are problems related to CPU states....
Code:
# dmesg | grep fail
acpi0: reservation of 0, a0000 (3) failed
acpi0: reservation of 100000, 7fef0000 (3) failed
hmmm, i got same thing on my Pentium 4 box
It's not hanging.....
Also what videocard do you use?
and do you have agp compiled in kernel?