I've never had the 1050 "forced into" 6.1 mode, even with 6.1 movies. In fact, it has a known issue (with early units?) where sometimes the sound will go out completely if you are in 6.1 mode and it is fed a 2ch signal. POOF, no sound. :-( I usually have to turn the 1050 off and back on to fix it. Annoying, but not fatal.

However, I have run into a couple of DVDs that do not work well. They use 2ch Dolby Digital, and it worked when I used a PS2 as the source. Now that I have a shiny new Sony player, with these discs, the speaker symbols blink off then back on, and the triangle blinks next to dolby digital, and it displays pro-logic. It seems confused, but it's not like I want to replace any of the components. I tried other 2ch signals, and it works great.

Could there be other "hidden flags" that confuse the receiver?

I think the work-around is to switch to analog audio with these discs. Not an ideal solution, but it works.