Hello, i have this problem, after 3 hours of setting these speakers and getting them to work i've come to this where realtek doesnt detect that my dvd reciever is 5.1, i've connected it thorough optical but it doesn't detect that it's 5.1.
front panel (green): http/puu.sh/ddb4Q/2760067564.jpg
it should be the other way around shouldnt it.
quick edit: i tried the dts and dolby digital audio test, they work fine.
+ if i go into a game, bf3 for example, 5.1 wont work.
We're talking optical [spdif] here, there's no 5.1 or 11.1, there's just singal. Your receiver will decode it as it's told to decode it. Try playing DTS/DD movie and see for Yourself. Try VLC, and remember to pick up the optical output. When You play music, You need to upmix the channels on receiver. Creative soundcards and Asus and others can upmix music by themselves, though, not the RealTek.
[in games the sound never works, unless they support dd/dts, which they don't. You need to set upmixing mode on receiver in order to play 5.1 ingame]
In general there should be tons of upmixing modes on Your receiver, so use one of them mp3s will always play only stereo [ac3 will play even 5.1], and games are pretty much "stereo" too, they do support 5.1 speaker systems, but only analogue, they'd need some licenses and stuff for DTS/DD. But there are some games that do support it!
There is actually even dolby digital and dts upmix mode, which works great with games. I'm using it a lot. There's PCM/THX/PLX DD mode I'm using atm on my Onkyo receiver. No idea what it means, but games sounds great with it [actually pcm is pulse code modulation , and I know what thx is, and it's dolby prologic II I reckon ]