CF-28S3 video corruption on Debian 5 "lenny" - SOLVED

I've posted this here for the benefit of Linux users on the CF-28 mark2/3. The rest of you will probably be pretty bored.

Problem description:

Ever since I installed this latest version of Debian on my CF-28, I've had this weird problem - small bits of garbled video (generally, black pixels) would appear in the very top of the screen... perhaps 2-3 pixels every few inches horizontally, in the top five or six pixel-rows. Within a few minutes of regular use, there would be more and more of these. Web browsing would accelerate this problem (probably due to the presence of images and constantly changing colors. After a while, my web images would become corrupt... they would start to turn mostly, but not entirely, black.

Also, characters within windows would randomly go invisible, only to come back after the cursor moved back over them. They were still "there" (for example, when typing and executing a command on the command line), but you couldn't see them until they moved. Similar issue with text within web pages. Just like with the garbled pixels, they would increase in frequency as time went on.

Switching virtual consoles (via Ctrl-Alt-F1, Ctrl-Alt-F7) would sometimes help, but not always, and it would become less and less helpful as the laptop's uptime increased.

It should be noted that this problem did not affect the virtual consoles (which were set to framebuffer mode 791, at 1024x768, the same resolution as my X11 display.

Solution, in brief:

Downgrade package "xserver-xorg-video-intel" from version 2:2.3.2-2+lenny6 (the lenny official version) to version 2:2.2.1-1ubuntu12 (from Ubuntu 8.04 "hardy").

Further details:

Other hardware likely affected: all mk2 and mk3 CF-28 units (the mk1 seems to use a different video chipset).

This seems to be entirely a software problem, not present in at least some older versions of the Xorg Intel driver.

I noticed that this doesn't happen in Windows XP Pro, or on Ubuntu 8.04 (run from a LiveCD). I tried upgrading to the Debian unstable "sid" version ( 2:2.3.2-2+lenny6), but this did not fix it. I tried to downgrade to the oldstable version ( 2:2.2.1-1~etchnhalf2), but this would not install due to a conflict with xserver-xorg-core. I wasn't feeling adventurous enough to downgrade the latter package.

The "testing" version of this package is the same as the stable/lenny version.

Using an Ubuntu package in place of a Debian one is possibly a risk, but so far it's working. I just need to ignore my system's constant desire to upgrade it.

I'll file a Debian bug eventually. :/

andy