Shutdown hangs at: "ACPI_power_off_called".

[Bill Stoye]

This stream has withered on the vine as I've been waiting for the full
Ubuntu release, in hopes something about this shutdown annoyance was
corrected there; I have done the following after the release, besides
the daily upgrades leading to it:
"sudo apt-get install ubuntu-base ubuntu-desktop"
"sudo apt-get install linux-k7"

I have tried the following parameters in Grub at bootup: "noapic",
"pci=noacpi", "acpi=off", "acpi=force" and "nolapic"; I have been
viewing and trying to follow any email that sounded like it pertained to
this shutdown problem; Shutdown still hangs at "acpi power off called"

Motherboard: SOYO; SY-KT600 DRAGON ULTRA PLTN
Processor: AMD Athlon XP 3200

The problem started after install "nvidia" driver and continues. It's an
annoyance for an otherwise great distribution and have hopes to correct
it without doing another installation, however simple. 

I was looking for a simpler system than the Libranet that I was using;
Libranet is excellent as well, just more than I needed and I was looking
towards using the support of the 2.6 kernel.

I don't have the ability to troubleshoot this on my own but I am
comfortable with a text editor and terminal.

Bill