After the last upgrade on my debian sid machine x.org kept crashing. This is an T42p IBM Thinkpad equiped with an:

There is a lot of information regarding this problem on the internet, below there is a list of bugs I found. It seems like it is a memmap related problem, see X.org #5450, debian BTS #345929 and a possible patch.

I tried several hints, like

• setting AGPMode “8″

• commenting out Load “dri”

• removing radeon.ko from my kernels module folder

but the only thing that worked was changing the device driver to vesa instead of ati in my xorg.conf:

Section "Device"
Identifier      "Generic Video Card"
#   Driver          "ati"
Driver          "vesa"
Screen          0
BusId           "PCI:1:0:0"
EndSection

Bugs in the debian BTS: #319689, #324717, #330968 and #345929

Bugs in the X.org bugzilla:#3911, #4324, #4486, #4847 and #5450