halt and poweroff do not shut the system down

Hello,

When I run 'halt' or 'poweroff' (sysvinit-2.86) the kernel prints:

Halting.
Shutdown: hdc
ACPI: PCI interrupt for device 0000:01:05.0 disabled
ACPI: PCI interrupt for device 0000:01:04.0 disabled
ACPI: PCI interrupt for device 0000:01:03.0 disabled
ACPI: PCI interrupt for device 0000:01:02.0 disabled Power down.
acpi_power_off called

But the system does not shut down. (The fans keep spinning, the LEDs
keep shining, the integrated LCD keeps displaying.) Basically, the motherboard is still providing power to every component, as if the power supply had refused to stop.

I followed the instructions given here:
http://bugzilla.kernel.org/show_bug.cgi?id=6431

cf. http://bugzilla.kernel.org/show_bug.cgi?id=9148

The system is an FWA-3140-CE:
http://advantech.com/products/1U-Rackmount-Intel-Pentium-4Processor-based-Platform-with-4PCI-LAN-Ports-2-PCI-Expansion-Slots/mod_1-23A2W4.aspx

The manufacturer is unwilling to help because they don't support Linux, and claim it is a software issue. I will ask them whether Windows is able to properly shut the system down.

What can I do to help fix the problem?

Regards.

I noticed the following message at boot:

* The chipset may have PM-Timer Bug. Due to workarounds for a bug,
* this clock source is slow. If you are sure your timer does not have
* this bug, please use "acpi_pm_good" to disable the workaround

Is there any chance that the two issues are connected? (It seems very unlikely.)

How can I tell whether the bug is fixed in my south bridge or not?
http://linux.kernel.free.fr/halt/lspci.txt

Regards.