My system has always been stable until C7.0, then I started to experience CPU overload and “crackling” audio noise a couple of times in every song.
The problem eventually went away with C7.05, but was reintroduced again with C7.06. Then I updated to C7.5, the problem remained. Then I updated with the new MR816 software which was released a couple of days ago. Still the same problem. Finally I updated the OS to Mavericks and now it works again! 
May i ask how old your mac is?
Did you have the audioproblems under 10.8 did then the update to 10.9 and the problems went away?
Im under 10.8 and the new driver didnt change anything.
I believe I got it in August or September 2009, because it was soon after Snow Leopard was released and it’s the 21.5" version, the cheapest one and I have upgraded it with extra RAM. (It’s in the studio, so I can’t check all the details now.)
I had the same experience as you. The new driver alone didn’t change anything, but after upgrading the OS from 10.8.x to 10.9.1 the problem was solved.
I don’t know if it will work for you and solve you problems, but it certainly solved my problems. 