I have three fans in my case (CPU, HDD and side fan). I have used my MOBO's utility software, Speedfan and Everest and although each shows that I have three fans connected, they dont actually show any values i.e. each shows zero.
My mobo is an ASUS P5N32 Deluxe running 1GB RAM and a P930D.
The CPU temps are all fine, idling at about 36-37degrees and I have used loading software at 100% to get CPU temp to a max of 49degrees and all fans are whirring nicely.