Yes, very weird. I never changed the temp trip in BIOS. It was set according to Acer specs. It has also been set to let the OS control power options.
The nearest thinking on this is that 7 & 8 reads the BIOS temp wrong and changes it's mind to run the fan at specs? I'm just not that savvy to know how it all works.
I've looked into updating the BIOS when I upgraded to 7 when it started happening and thought I might have to with 8, but I figured it works, so why fix it? I'm frugal with my money also. Why shell it out?!!