AMD FX-4170 Stock Fan Issues

[I apologize if this is the wrong forum.]

Hi there! I have been having some odd sensor issues with the stock FX-4170 fan for my new build. Sometimes the sensor from Hwmonitor and the AI FaxExpert say that the CPU fan stopped spinning, but I have watched it during some of those times and it never stopped spinning. Is this a fan issue or perhaps something with the motherboard? Is there a way to fix this?

Thanks in advance!

MB: ASUS M5A99X Evo
CPU: FX-4170
VGA: XFX Radeon 6870 2GB
RAM: AMD Performance Edition 8GB 1600Mhz
SDD: OCZ Agility 3 120 GB
PSU: Corsair GS 700W
Case: HAF XM
Fans: All stock, no extras