Bug#386290: #386290: xserver-xorg-video-i810: i810 driver causes hangs on 82830 (ICH3)
> With Xorg 6.8 and above, using 24 bit color, with any amount of stolen
> memory and apparently any other combination of options, causes the
> machine to lock up if the system returns from console to X11 for any
some patches were applied to xserver-xorg-video-i810 1.7.2-2 which
fixed certain lockup bugs. Using the most recent version of the
driver, does your computer still experience lockup under 24bit colour?
If it's still there, the X log (/var/log/Xorg.0.log or Xorg.0.log.old)
might possibly be useful to us.