The 2.6.31 kernel makes your system boot and run faster, no doubt. However, combined with newer rendering code in the latest versions of Xorg, the older Intel chips throw a fit (especially the 82845). The easiest fix seems to be to add "nomodeset" to the booting command line in GRUB/LILO: there are other possible fixes and workarounds (I found out later that blacklisting the i915 module helps too).
* Gentoo Linux documentation on the Intel driver: can be used with most other setups.
* Workaround/fix on Gentoo
* Redhat bug regarding problems (where I found the "nomodeset" fix)
* UXA workaround on Ubuntu Karmic
* 2.6.31 use on Ubuntu Jaunty
* How to blacklist the i915 module
* Forcing the old Intel Xorg driver back in on Jaunty
A workaround that worked good on one system and didn't at all on another was using the plain vesa driver. A very basic xorg.conf can be written with just the following...