Graphics Graphics Card Buzzing (HELP!)

Recently bought a XXX 4890 XXX Edition.

Whenever i ramp it up in an intense game – it buzz’s quite loud. For example, on Crysis it’ll buzz quite loud at start up / menus and then quiet down a bit after couple of minutes in game.. But it’s still slightly there. If i turn off vertical sync in CS Source (so obviously FPS goes to max) it'll start then to.

I’ve googled the hell out of the issue – most saying it’s a common occurrence (on both ATi and Nvidia cards).. But not an actual problem. Opinions vary on a solution.. From people getting replacements and it being fine, to most getting replacements and completely different cards and still having the problem. Some also say it could be a PSU problem, with some saying a more sufficient one would solve the problem.

I’d like people’s opinions on here..

1) Should i return for a replacement (Doesn’t seem much point if it’s a common occurrence and not damaging anything)

2) Should i purchase a high wattage PSU

3) Do nothing.

Setup:
- i7 920
- 6gb corsair dominator DDR3
- MSI x58 Pro
- 2x 1TB WD HDDs (I tried unplugged one to see if it happens, to lower power consumption. Same thing occurred)