HW monitor says zero revs on cpu cooler

Hello. I´m using HW Monitor for watching my rig. Athlon II X2 250, Arctic Freezer 64, Gigabyte GA-MA 770 UD3. Clocked to 3.6 GHz core, 2160 MHz on NB and HT link.

The sytem runs nice and cool in my Antec case, 23/33 C idle/load oon cpu, so I really don´t think there´s anything wrong.

But from time to time, a couple of times a day maybe, I can see, that the speed of the cpu HSF value reads "0" in the min. tab.

When I first saw it, I stared at HWM till my eyes were square, and after a long wait I saw the fan apparantly stopped for maybe a second and then immidiately returned to 500 rpm again as if it never happened. And now I have seen it for the other fan i have on the other side of the HS for pull as well: down to stop for about a second or so, and then back to normal.

Both are attached to the mobo with three-pin headers.

If it is the powersupply or the mobo, I should fix it before something happens while I play. But if it somehow is something with a sensor or the software, everything is fine.

Have anyone had similar experiences?

Kent Thomsen, DK