It could be the television - there's a distinct possibility that Samsung Australia would probably be able to answer better than I would.

That said, even though the channel may be broadcasting in 5.1 (meaning that you'll get the signal) that in and of itself doesn't mean the show was recorded in 5.1, and for that particular show, it may not be available.

If nothing else, a call to service might help resolve the issue, or you can discuss it further with them - they'll be able to do far more than I would from here.

I hope that even though this doesn't solve your issue, I'm able to point you in the right direction.

Keep me posted!

--HDTech