Hi, i received my 670 yesterday and although the card is amazing, I'm having a small noise issue. Basically, if you've seen the card it has 3 fans. And although these fans are pretty much silent, 1 is giving me problems. It is as if the middle of the fan circle is rubbing/brushing against something and making a small noise. Now, although the noise is pretty unaudible unless my ear is next to the PC, it still bugs me. Do you guys no if this is normal? Is there an easy fix? Or is it worth replacing?