I have acpi. How can I get the computer to "sleep"? I tried these:
echo 0 > /proc/acpi/sleep #Result: nothing
echo 1 > /proc/acpi/sleep #Result: X freezes
echo 5 > /proc/acpi/sleep #Result: nothing

what does this give you?

cat /proc/acpi/sleep

It says "S0 S1 S5".

try one of these

sudo echo 0 > /proc/acpi/sleep

sudo echo 1 > /proc/acpi/sleep

sudo echo 5 > /proc/acpi/sleep

How's sudo going to help? I did it as root (if I do it as someone else it says "permission denied"). Also, I heard the nvidia drivers might cause problems. Could this be the issue?

Well I tried your sudo suggestion, and it was the same as it was without it. I also did a few experiments. Echoing 1 to /proc/acpi/sleep just made the computer stop responding to input. I tested it in runlevel 3, and got the same result as before. However, the computer still reacts to the power button, which shuts down the computer. I edited the /etc/acpi/acpi_event_handler.sh, replacing "/sbin/init 0" with "/bin/echo 0 > /proc/acpi/sleep". Now I can get the computer out of the input freeze. Or maybe it was an output freeze? Anyways, right now what echo 1 > /proc/ac... does isn't very useful. How can I get it to work properly?

see if this helps you out at all

http://acpi.sourceforge.net/documentation/sleep.html

Has anyone succesfully used acpi sleep? What did it do, and how was it done?

Well I tried switching to S1 in runlevel 1, that gave me a messge about switching to S1 that i didn't get in the other runlevels, but that's all. Any ideas?

Bump.