Also, what happens when you select 'matrixed surround' (or equivalent)?
I've just bought a Samsung HT-E6750W and have discovered that while the rear speakers are great when watching a Blu-ray disc, they don't output any sound if you're playing music from an iPod or CD. The manual suggests that it's supposed to function that way. I probably wouldn't have bought it if I'd realised that - assumed it would function similarly to my old surround sound system.
Has any-one found a work-around to make the rear speakers output sound when you're listening to music?