CPU Heatsink Fan Speed Goes Up And Down

[robot]

My CPU Fan speed goes up and down at will
I have tried setting it to a constant speed or tracking CPU Heatsink temperature but to no avail.
It is currently set to a fixed 1000rpm but goes to 3800 then to 2500 (ish), then back to 1000.

[Steven]

Is (was) any other fan controlling software installed?

http://forums.crystalidea.com/viewtopic.php?f=11&t=1006

[robot]

Yes.
Uninstalled it and its now calmed down.
Your app is the only one I need, clearly.....
Thanks