So. After five hours - seven, but that included two talking to my mother - I had a Kubuntu install that booted. Woot!
Time to add software!
Install XChat. Start using it. System crashes. As in, GUI stays as is, mouse moves, clicking doesn't do anything, anywhere, and ctrl-alt-f1 doesn't bring up a VT. Nothing except the power button does anything.
Reboot.
Install GIMP, Firefox, Pidgin. At some point, it crashes again, in the same way.
Reboot. Establish that a VT is accessible in the normal way when not crashed.
Start configuring Kopete and trying to get XChat to beep when it's meant to, etc. Another, identical, crash. Definitely, VTs not accessible at this point.
Reboot. No sign of errors in /var/log/Xorg.0.log or ~/.xsession-errors.
Check the IP, so I can try from here to see if it pings, if it happens again.
Look in Additional Drivers. Activate a current version NVIDIA accelerated graphics driver.
Establish that Kopete is horrible, and keeps giving Mike multiple messages; revert to Pidgin.
Faff a bit more. Another crash.
It pings, but I can't ssh into it. Reboot, therefore.
This is ... a long way from funny. XChat's been running each time this has happened ... possibly also Firefox.
Upon recommendation, I've checked which kernel I'm using. 2.6.35-28-generic-pae - the latest long-term stable. So that probably shouldn't be it ...
Perhaps I should install and/or start running an sshd thing so I can try sshing in again? If it's an X problem, which seems likely, it might be possible to tell.
I'll do that when I've finished downloading and installling all the necessaries for KPhotoAlbum and LaTeX, which are currently in progress.
Time to post this entry, as it's been ages.