Comment 272 for bug 43961

The shutdown/reboot was also hanging on my Acer Travelmate 290 laptop. I'm running Hardy Heron 8.04. After reading this thread, I tried a few things, and the grub menu setting that has had the most success is this:

acpi=force nolapic

I can now (knock on wood) shutdown and restart properly. Before, both processes would hang almost immediately--there was not even a splash screen, just black (no activity shown on the hard drive LED, but the fan and my USB external drive were both still running). I had to physically power down from there. But the grub setting above seems to have worked for both shutdown and restart.

However, the system still will not suspend or hibernate properly. It will not resume from suspend mode--forcing me to physically shut down with the power button (*shudder*).