[kwlug-disc] laptop hang when switch to battery

[richard at weait.com]

It was fine before the distro upgrade.  It was 8.04, then I upgraded this
afternoon.

Thinkpad T60
Ubuntu 8.10 (Intrepid Ibex)

Runs fast, new Ibex-y widgets are cool.
Even hibernate and suspend work right!  Those did not work with Heron.
But it's a laptop...  and when I unplugged the AC to go on battery...
Screen freaks out.
caps lock won't respond.
can't alt tab to a text console.
ctrl-alt-backspace doesn't restart X
ctrl-alt-del doesn't reboot.

Hard power off works.  Reboot with AC unplugged is fine, runs from battery
as expected.  Add AC power, after booting from battery is okay.  Screen
gets brighter as backlight goes to higher settings. All normal.

Remove AC again, no problem.  Replace AC, no problem.

Wait a while and remove AC and it freezes again.

Thoughts?

Best regards,
Richard