Hard disk power cut too early during a halt

[Ian Melnick <dazed@vonsteuben.cps.k12.il.us>]

Hello, all

This problem has been happening for as long as I can remember... since I
enabled ACPI power management (this comp doesn't do APM afaik). Kernels in
question are from 2.4.17 to 2.4.20, I think (didn't use power management
before that).

I have two hard disks in this machine, hda and hdb. During a shutdown -h
whatever, it gets close to the end of the line and says something like
"Unmounting local filesystems...done". Then the power on one of the
drives (dunno which one) clicks off and clicks back on really quickly.
Then it says "Finishing something something hda hdb", and at that point
both drives click off simultaneously.

Didn't have this problem when there was only one hard disk in the
machine. I've noticed this on two different computers - A Dell Optiplex
GX1 with its original bios, and a Dell Dimension T something with its
bios updated to the latest release. It has the same problem before and
after the update, so updating it was pointless.

Has anyone else had this problem? Is there something I can do to solve
it (other than not using power management)?

Thanks!
Ian