maybe its a kink in the fan....or its speeding up, make sure its secure on the card and as long as your not having temperature problems it should be fine.
-I'm sorry, but the UN must be firm with you. Let me in, or else.
-Or else what?
-Or else we will be very angry with you... and we will write you a letter, telling you how angry we are.
ru sure the noise is from your card, i could be from any of the fans in your PC for example (note please dont start unplugging them unless u want a barbecue)
Trust me I know what I'm doing... ooops, grab the cat...