So i just updated to the 7264 driver posted on the crackling problem thread, and man. What a difference its like night and day this driver is really really good. I did not have to modify the registry the crackling was gone and the sound is amazing no...
MY biggest problem is that middle sounds are so very low with these new drivers. Watching movies using the speakers is pretty bad. The middle sounds like voices are so low. If you switch to 5.1 it uses the subwoofer as a speaker and the middles there...
I actually read a thread a while back of someone having similar issues to yours. They fixed it by installing QuietHDD. The problem was the hard drive energy saving feature.