2.6.38 introduced screen corruption with Intel GPUs. Many bugs reported: NONE fixed !
Here are some of those bug reports (there are more) :
[915GM] font corruption on Intel GMA900 :
[i945gm] Screen Corruption with new Xorg stack with terminal programs :
xserver-xorg-video-intel: Typography distorted by the kernel 2.6.38 :
linux-image-2.6.38-2-686: Console turns black during boot :
xserver-xorg-video-intel: sporadic graphics corruption after upgrade to 2.6.38 :
Corrupted display, unusable X-Server after using Chromium for some minutes :
Multiple display corruption with 2.6.38-x kernels on 865g :
[915GM] Characters sometimes have horizontal lines through them (glyph font corruption) :
Some pretend to have fixed it, but later someone points that it is not fixed or the bug appears less often, some bug managers declare the issue fixed even though the last message from a user declares that the screen/font corruption is still there. What an horrible mess !
I have these bugs with kernel 2.6.38, 2.6.39, 3.0.0.
I upgraded all the graphics packages several times in Debian Experimental. The bugs are still present. They only disappear if I go back to 2.6.37. I have an Intel G33 GPU.
For the second time in a few days, I have seen it triggered by an image search in Google/Images, using Firefox 7. I checked the timing with dmesg and uptime.
Also : bug reports about "[drm] MTRR allocation failed. Graphics performance may suffer" offer solutions that do not work, like GRUB_CMDLINE_LINUX="enable_mtrr_cleanup mtrr_spare_reg_nr=1".
It is incredible to see so many bugs closed after false solutions are given.
I suffer from these bugs and no solution works. The latest kernel in Debian Experimental 3.1.rc4 changes nothing, neither do the latest graphics packages.