Get 5.1 surround from Gigabyte EP45T DS3R Motheboard

Got this exciting (according to the salesperson) new motherboard that offers 7.1 surround support. (Gigabyte EP45T-DS3R)

http://www.gigabyte.com.tw/Product [...] uctID=2851

Yet all it will do for my 5.1 setup is front side speakers and main console. OK, maybe woofer. I have selected 5.1 setup in Windows XP Pro's control panel.

I have Realtek Audio, latest driver I think, and have tried different configurations in their test application. Still, I get EITHER the front right and left OR the rear right and left speakers--but not both at the same time. Also, I know the speakers work because there is no problem doing 5.1 from my old computer's SoundBlaster card.

I contacted Gigabyte and was told that unless my media is programmed for 7.1, I'm stuck with just the front two speakers.

I can't buy that story. Especially as I can't even get the 5.1 to work with the Realtek Audio test application.

Does anyone know what might be the problem?

By the way, I have Logitech speakers (5.1, "Z something" ) from a few years back, but they still plug into the same jacks on the sound card, so I doubt it's the speaker hookup.

Thanks.