The Ubuntu Live CD worked straight away for the laptop: I was able to boot into a temporary copy of Linux using the VESA display drivers, and test sound, CD and other peripherals (obviously) and wired networking. However, optimising the system wasn’t so easy, and as I say Nick practically installed Ubuntu for me, fixing all that he could.
Below is a list of the main fixes and workarounds that Nick employed, for my reference as much as anything else.
Now that Gutsy Gibbon is fairly mature, I’ve managed to upgrade my machine to it and am now running the 2.6.22-14-386 kernel. More importantly, with a minimum of fuss I now have video, wireless and sound!
In brief: the problems discussed here and here go away under the most recent Ubuntu release, Hardy Heron, which I can generally recommend.
Alsa seems stable and graphics support is present from installation onwards.