I know this is an old thread, but I recently started experiencing this issue and wanted to add my AVR to the list with this problem.
I have the Sony STR-DA5500ES.
I get the problem consistently on the Stand By Me title at ~32:23. However, I also get it inconsistently, i.e., sometimes it happens and sometimes it doesn't. I've heard the pops on Stand by Me at least in 4 or 5 different places.
It also happened on TRON Legacy at the end of Chapter 11 as the elevator was plummeting around 1:18:40 to the end of the chapter. I thought my speakers were going to fry it was so bad.
Only happens when bit streaming to the AVR. If I use LPCM (Oppo BDP-93) I have no issues. Also, I do not have this issue with the LG BD390 so I don't know what to make of this.
Isn't bit streaming the same regardless of the source? If that's the case, why do I get the pop from the Oppo but not the LG?