Hello,

Thank you in advance for any answers and apologies if this thread exists anywhere else in the forum.
I have done multiple searches through my manuals, friends, other forums. I have not rung sky yet.

My equipment:
Mysky- no HD ticket.
Hdmi connection to Marantz Nr1602 Receiver
Hdmi out from receiver to LG 3d tv. (47LW4500)
Speakers Klipsch HDT-500.(5.1) 
2nd zone speakers not connected at this stage as I trouble shoot this fault.

My Problem:
Basically, I *believe* I have a reasonable ability in setting up hi-fi etc, I have a problem where currently if the amp is in auto mode, I select a movie from sky movies that should be broadcast in 5.1, the receiver distributes it in stereo only. If I change the channel to channel 1, 2 or 3 it will broadcast it in dolby digital.  

I have confirmed the receiver operation is good in auto, the sony blu ray player in auto will play my movies in DTS, dolby 5.1 and so on. I have checked that the sound coming out of the sky box is dolby not mpec/pcm on both HDMi and Spdif outputs (not currently using optical though) in the setup menu.

If I manually change the surround mode on the receiver to DTS or dolby whilst watching a movie its clear that it's not  the real deal. Also, I have had a look through the marantz manual and have the sound passing through amp as opposed to the tv, I hear sometimes if the ARC is enabled,the tv will tell the amp I cant process dolby and thus the stereo output occurs. 

I am a little stumped, my next option is to ring sky themselves, but this is a hard one to diagnose, it has surely just got to be a setting problem I am unaware of. Thanks for taking the time to read, and help , if you can. I also don't want to run optical from the sky as my xbox is pre HDMI, I am using optical from the xbox in to the only optical input on the receiver.
Cheers,
Gareth.