I have that exact same board. The temperature probes are f***ed on that board. Don't expect to ever get a good reading from it.
I get three different readings from my CPU. In bios it says 31 idle. But when I heat it up, the fan speeds up before the reading goes up, so that can't really be the CPU temp. Also, in SpeedFan, it reports at 52. The only one that seems to be right is the provided overclocking program, which seems to report my CPU at 27 and raises simuotanously with my CPU's fan speed.