Other Help Topics :: trouble with apm/acpi? this may help

Back when DSL used the 2.4.24 kernel, (DSL 0.7), APM worked well for me. Then I noticed around DSL 0.8, the kernel went to 2.4.26 and it was apparently based on a new Knoppix version. This broke APM stuff for me, because now ACPI is in there too and was taking over.

I fixed this by modifying /etc/lilo.conf. I added acpi=off to the kernel boot line, and APM started working again.

For what is is worth, I use a module called powerswitch.o that will cause a power button press to gracefully shutdown the box (shutdown -h now) instead of suspending the box which is the linux default.

original here.