You are not alone. Mine is from the right rear channel (7.0 setup). I straight swapped the phonos and speaker cables to the rear amp to prove it was the 568.25 and not later in the chain. There is a low-level mid-range pop noticable on quite sections or occasionally after a mid-bass note from the front L&R.....

I had only noticed it on playback from Sky+ hard drive using DPL2THX on compressed channels (e.g. Hallmark) and assumed it was momentary loss of signal/lock. Never experienced with a DD or DTS source.

You have got me thinking. I will test with other analog and digital sources to focus on the culprit component.

Anyone else?

In the spirit of Spinaltap, I would like to confirm that I am not involved in the corrupt theft of a global sport.