I too have the exact same problem. I have the H20 HD receiver and it will periodically pop during a HD show. It seems like for some reason, it is dropping the digtial signal and re-locking which causes it to pop. If you change the H20 setting (which I did because it was so bothersome) to PCM vs. dolby digital, the problem will go away. I have the same problem w/ my DVD player when it goes between the menus and previews. I would describe mine as a medium pop as it is very noticiable. I was hoping the latest firmware would fix whatever was wrong, but no luck.