5.1 surround sound

[taxman48]

Does anyone else have a problem getting surround sound from the STB? I have the new Samsung with optical out to AVr, and display on receiver still says "Stereo".. AVR is Pioneer Elite . I also have an hdmi from box to AVr in case box doesn't put out Dolby sound.. I notice over at AVs there are quit a bit of same problem posts. I will try and swap out an upstairs SA box with downstairs box.. thanks in advance