I came across something that might be relevent to your search, Cargo. It seems that the HK AVR-635 has a software bug that could be a major headache, particularly for anybody using a 6.1 or 7.1 speaker setup or trying to use Logic7. The way the unit recognized Dolby flags causes it to always switch back to straight Dolby Digital - so if you want to use Pro Logic IIx to get surround back channels running or you prefer to use Logic7 all the time, you have to manually select it each time the signal resets (which includes changes in the signal format for commercials on some HD channels, changing channels on satellite or digital cable, and even pausing and re-starting DVD's). HK is working on a software fix for the 635, but there's nothing available yet that I could find. There's a lengthy thread at AVS about this issue and the 635, but it doesn't say if other units in HK's current line (which presumably share at least some software) are also affected.