garbled audio

I left a detailed post earlier, no one responded, so here's a simpler post:

My system:
Dell Dimension 4700, Pentium IV (3.0 GHz), 1.5 GB of RAM
Windoes XP Home Edition, Version 2002, SP2
NEC 3550A DVD-RW, Sound Card: SoundMAX Digital Audio

Problem:
DVD audio sounds fine coming through USB headphones, but very garbled coming
through the desktop stereo speakers. No amount of troubleshooting has helped
this situation. If anyone has a clue on this one, I would appreciate any
advice.
thx-
c.


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