I have the HK 520 reciever. On some TV channels, usually my high def. channels, it will activate Dolby Digital with Pro Logic II at the same time. I don't mind this but it doesn't send a signal to my sub. It also won't let me switch to any other mode. This also happened on a DVD the other day....not a movie but the Alice In Chains Unplugged DVD. Is there anyway around this so I can get my sub playing when it goes in this mode?