Silent Boost Fan Question

[risk_reversal]

I recently (yesterday) installed the Silent Boost A1889-01 on one of my pcs. After installing it, and starting pc, the boot sequence stopped at the post screen and a message saying 'cpu fan not operating' can up with a buzzer. However, I had the side of the case open and could see the fan spining before this message. I continued the boot process and got a monitoring utility up and there appeared to be no problems.
I then rebooted (fine no message or buzzer) went into bios to 'PC Health Status' and noted the 'Cpu Fan Speed' and this is what it does. Whilst most of the time it registers 2600 rpms now and again it goes to 0 rpm (as in 2600>0>2600 nothing in between) for a moment and then goes back to its normal speed. The fan itself does not appear to be slowing down at all. Also as I said, when I was monitoring the fan speed by way of a monitoring utility there was no such problem.
The motherboard connector is fine because the other cpu fan that I removed did not have any issues like that.

Can anyone please give me any clues. Could the fan be 'defective' in this respect. Anybody ever experienced anything like this.

BTW running this on an MSI KT3 Ultra2 (KT333), latest bios v5.7

[flanzig1]

Double check the fan connector for being fully seated on the mobo pins, see if one of the pins may have backed out of the fan connector, or a poor connection at the fan.

[risk_reversal]

Many thanks for your reply flanzig1. Tried reseating the fan connector several times & also could not see that anything was loose on the fan wiring/plug.

Have run across some info which says that sometimes the mobo CPU sensor has trouble detecting low RPM fans & that 2600RPM is the range in which this detection problem occcurs. Have you heard of anything like that?

Whilst watching the CPU RPM fan counter in the bios I did notice that all speeds above 2600RPM where recorded but nothing below.