The random lock ups on laptops w/ intel drivers is a known bug.
Here is the bug report:
Symptoms include keyboard lock ups, mouse still active but cannot
click or select anything, only way to reboot or shutdown is to hold down
the power button. Version 2.5 of the intel driver has the fix.
Um... using xorg-x11-drv-i810-2.5.0-4.fc10.x86_64 here, what fix?