Well, then, I don't know. Sorry.
Maybe a wiring problem? In the "Speaker Settings" dialog box, under the "Speaker Test" panel, if you click on "Channel," do all five speakers (FL, FR, C, RL, & RR) produce sound? (She'll say, "Front Left," "Front Right," "Center," "Rear Left," and "Rear Right.")
Also, if you play something via Windows Media Player, do you get 5.1 output?
If both of the above produce positive results, then I know it'll
seem to indicate that MC is the problem, but I am almost 100% confident that this is
not an MC issue regardless. My only suggestion is to make sure (for testing purposes) that all plug-ins are disabled (in the DSP Studio box, make sure nothing is checked).
Also, you can try all three output devices: Wave, DirectX, and ASIO. (NOTE: If you try ASIO, you'll need to enable the "Output Format" plug-in in DSP Studio and set the
Sample Rate to 48,000 Hz--leave
Bitdepth and
Channels set to "source.")