Auto-Resume of CPU fan not working on IC7-G Max II

Just wondering if anyone else has seen this:

Set CPU fan throttle to xx% (in my case 60%) in system bios.
Also set it to auto-resume full speed when CPU temp reaches
yyC (in my case 60C). Start Win2K, fire up a stress test and
watch the CPU start well under yyC, and eventually go well
above yyC and stay there -- but the fan never resumes full
speed.

Not a big deal really, just more curious than anything. This is
an ACPI installation so I don't understand why this feature
isn't working. Is this auto-resume part of the ACPI spec? Is
it a problem with Win2K?

Thanks..