Having no programming skills but a fair amount of Beta test work in many programs and a few operating systems, please take the following with a grain of noob salt...
It appears that the issue may be the fault of having APM and ACPI active at the same time.
I have had this issue in the past and when I do - I simply go in and turn off one of the two (APM for newer systems gets turned off or ACPI on older pre-2000 systems) and this resolves the issue instantly with a reboot.
Having no programming skills but a fair amount of Beta test work in many programs and a few operating systems, please take the following with a grain of noob salt...
It appears that the issue may be the fault of having APM and ACPI active at the same time.
I have had this issue in the past and when I do - I simply go in and turn off one of the two (APM for newer systems gets turned off or ACPI on older pre-2000 systems) and this resolves the issue instantly with a reboot.
I hope this helps.
Cheers,
BinaryFu