It's been awhile since I posted here, things seemed ok after updating to 4.1, but that didn't last. The noise returned in full force, it just makes no sense. Anyway, I updated to 4.2 yesterday (am a developer) and the noise is definitely still there. I spoke to the dealership and they said there is a fix for one type of radio, but not the one I have (2010 yukon with nav and dvd), didn't ask him which radio the fix was for, I'm not sure the fix is even for the problem that we are all having anyway. I have begun using the headphone jack cable when it gets too annoying, which is ridiculous to have to do, but it sounds much better.