Has anyone else experienced this? I have an R15 hooked up to my receiver via the digital ports and whenever I watch a show in 5.1, although my receiver indicates that it is decoding a 5.1 signal, there is never any sound on the back speakers. I only get sound out of my front speakers, center, and sub-woofer. I see this with all the premium channels (HBO, Showtime, Starz, etc.) that encode in 5.1.