There are two workarounds:
1. Disable acpi. Add acpi=off to the kernel line in /boot/grub/menu.lst 2. Downgrade the kernel. I only suffer the bug in 2.6.20-16-generic, but NOT in 2.6.17-10-generic.
There are two workarounds:
1. Disable acpi. Add acpi=off to the kernel line in /boot/grub/menu.lst
2. Downgrade the kernel. I only suffer the bug in 2.6.20-16-generic, but NOT in 2.6.17-10-generic.