Digital sound doesn't work--analog does (Asus A8N-SLI Deluxe)

[magnublm]

I have the Asus A8N-SLI Deluxe board, and I'm using the on-board sound controller out of the rear. I don't have the front one hooked up. Sound works if I have *analog* speakers plugged in to the audio out/front speakers port. When I hook up my *digital* left and right speakers to the same port, I get nothing. Windows XP (SP2) sees the card fine and thinks it's playing sound without error, but I don't hear anything. I don't see any place to "send digital sound only" either. I'm using the Realtek AC'97 audio driver that came with the Asus motherboard CD.

Any ideas? Thanks for the help in advance.

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magnublm