Linux doesn't shutdown (turn off) the computer

["Dâniel Fraga" <fragabr@gmail.com>]

	I've been using Linux since 1997 and started with Slackware
3.1 with an AT case.

	Then some time after, I upgraded the system to a ATX case and
ATX power supply of course. Unfortunately Linux never turn the computer
off after shutdown. It *always* stay at the "System halted" screen and
I have to press for 4 seconds the power button for the computer to
turn off.

	With Windows everything works perfectly...

	I tested this Linux system with 3 different motherboards and
the problem remains.

	So, is it a ACPI issue, configuration? What logs or information
do you need to properly debug this?

	Now I'm using Linux 2.6.33.

	Thanks.

	Ps: my question is: what happens after the "System halted"
message? The kernel sends a signal to the motherboard, BIOS, whatever
to shutdown the computer? Maybe something is blocking it? Thanks.

-- 
Linux 2.6.33: Man-Eating Seals of Antiquity