Just thought I'd add that I'm getting popping as well, when I change channels on my new Motorola dual-tuner DVR cable box. Didn't have this problem with the old single-tuner cable box. It's a very quiet pop, like static, and not that big a deal.
The DVR is having it's own sound issues (often looses sound entirely when recording), so right now I think it's related to the source, and not the 950. In program (once the digital audio locks on) I have no sound problems.
I will try the unplug trick and see if it helps.