Yeah, I'm not convinced are issues are the same, though they seem related. From reading your posts your crackling was happening on a timed interval, where as mine is more of a random static.

I have a laptop as well, but it is going on 5 years old, and this problem is new since kernels .33+. I don't think I have this new USB bus/hub that you are talking about. That said, doing 2.6.39 with rtirq and nokms is the only way to solve it in my case. That or use a really old release of a distro, which gives me other issues non audio related.