I have a Dell Inspiron 1100 and when i close the lid of my laptop the screen doesnt turn off, it turned off before i installed acpi and acpid, but the battery monitor, temperature and throttle didnt work.
I have tried these commands on lilo and none of them work
1) acpi=ht
2) nolapic acpi=on
3) nolapic acpi=off
4) nolapic noapic acpi=on
5) nolapic noapic acpi=off
6) no commands

When i type acpi -V i get the status. But when i write tail -f /var/log/acpid nothing happens when i plug or unplug my ac adaptor.

I have Mandrake 10 installed with no kernel modifications.
It also happend with Fedora Core 1 and 2
Please Help!

when i use acpi=ht, when i close the lid the light turns of but the battery monitor is dead

What is the BIOS version on your laptop?
Its well known that the recent versions of bios in 1100 has faulty dsdt which prevents all acpi functions from working correctly.

On my laptop, the lib closing event is correctly detected, by the suspend action doesn't work.

check
http://www.geocities.com/randomnumbergenerator2001/
for discussion on this.
Discussions in dell user forum indicate that dell tech support people are aware of this.
Lets hope they fix it soon.

I have the A029 Bios