What you describe is exactly what happens when my DVD player is set for 5.1 channel output but playing a 2- Channel disk. Yes, you have to go through a couple of menus to change the setting manually every time you want to use 5.1 and then go back in to change it back. It's annoying. I bet your problem is something similar.

Chris Herzog

"The Devil's on the loose and he's dancin' with the Mummy!!!"