Static/Crackling/Popping Noise *when enabling SLI*

Hi guys!
Just got my new PC:

Gigabyte X58A-UD3R
Core i7 930
2XGainward GTX 460 GS
Thermaltake 900W PSU
6GB (2X3) Dominator 1600MHZ

Only about a week ago, and I'm struggling with SLI...
At first - it gave me weird flickers (even at menus), I tried a few things, fixed it, either with drivers, or when I flipped the SLI bridge... not too sure.
anyway - it's ok now.

BUT (!) now I got a new problem:
When I hear music - there's a really crappy popping sound.
More so - whenever I move my mouse around.
Disabling SLI fixes it, but I didn't buy 2 cards to use 1 as a paperweight.

Tried everything driver-related, I believe... used driver-sweeper and all

Please help if u know anything,
Thank you

update:
Checked the "SLI zone" site, and the gtx 460 isn't showing under the "supported PSUs", however - the dual-470s PSUs ARE detailed, and my (appearantly) old thermaltake 900W is NOT there.
Maybe my PSU is too old?
I got this model:
http://www.thermaltake.com/product [...] 900&ovid=n
It says that it supports SLI, but maybe not the new models?

I'm trying to replace it tomorrow with a Corsair TX950W... this one does show under the dual-470s supported PSUs.

will keep you updated, but my question is basically this:
do I really HAVE to use the ones supported at SLI zone, or if the manufacture says it's sli-ready - then it's sli-ready (no matter what model)?

Didn't help much... seems more stable, but there are sound problems just as before....

Any other ideas maybe?

I believe that it maybe your board at this point so I suggest that you give a new sound card a try or a old one that is pci. If you still get pop then its your sound system.

Well I don't know what to tell you since there are often rather unique problems that show up from time to time and any one who has worked in IT or in the electrical feild can tell you that. So I would just try any old pci sound card to see if you still get the pop or not to rule out the sound system of at least the jack/plug on the board. Try another pc or laptop if you are able to save on effort. Beyond that it is likely the board or very bad drivers and when it comes to software data corruption is much more common than people think.