ACPI broke going from 8 to 9

[Dan Allen]

I just upgraded my Dell OptiPlex GX270 from RELENG_8 to RELENG_9.  The machine no longer boots.  However, if I put

  hint.acpi.0.disabled=1

in /boot/loader.conf then the machine runs fine.  With RELENG_8 the machine had no loader.conf, and the power button worked on my desktop machine.  Now with ACPI disabled my power button does not work.  I have found that the machine hangs at boot during a scan of the PCI bus, but if I disable that (hw.acpi.disable=pci) then the machine cannot find a boot drive.

So I have lost functionality that worked fine in BSD 8.

Thoughts?  Suggestions?

Thanks,

Dan Allen