Headphones making ringing and wavy static noise only in windows

I have my mac "quad booted" between 10.5.x, 10.6.x, win7 and ubuntu. Under 10.5, 10.6 and ubuntu, the sound works flawlessly. however, under windows 7, whenever there isn't any sound playing, or there is low-volume sound, the headphones will make chirping ringing, and static noises. They appear to be in a pattern, one that changes depending on the last system-sound played (i.e back button in windows explorer, or ventrilio talk sound...) or while changing volume. This issue has occurred with bootcamp drivers 2.0, 3.0 or 3.1, or generic realtek drivers, under Windows 7. (both the beta and final ultimate versions fully updated) Windows 7 has been re-installed multiple times, and these sounds have been confirmed to happen before any software other than drivers are installed.

I can't seem to find any solution that fixes these sounds. I know that it isn't hardware related because my other 3 OSs do not make this noise. Any help would be much appreciated.

I have a Macbook pro 4,1 (15" 2.4ghz Penryn, 4gb ram, 8600gt)

*also sorry for the double post, I was told that although my mac was sold in late 2008, it belongs in this sub-forum.