Comment 34 for bug 280805

I don't know if this will help but I should mention that the identical issue happened on Vista.

I have a dual boot and I hadn't upgraded my Nvdia Vista driver since I installed Vista around last March/April. Last week I decided to upgrade the Vista nvidia driver (from the Dell website) in the hopes of correcting a resolution changing problem. After updating the driver and rebooting Vista the alternate fan speed (alternating fast slow every few seconds) problem started. I upgraded the bios from A10 to A12 and the fan resumed normal operation.

I also then changed from Nvidia 173 to 177 on Ubuntu and the fan is working normally.