I've got a V5, with K6-III+ running at 400Mhz.
I bought this Xitel Pro HiFi-Link, hoping to use it to output MP3's to my home theatre receiver. www.xitel.com
So I hooked up one end to my IO via my USB hub, and the other end to my receiver via the included 30ft. digital coaxial cable. But I couldn't get MP3s to output to it. I could hear the windows startup theme, and other .WAV files when I tried to play them through the SOUNDS settings in the windows Control Panel -- but not MP3 files when played with Windows Media Player (or even Winamp). Internet streaming radio from my web browser played fine. Media Player would indicate that the MP3 was playing, but I got no audio whatsoever. If I switched back to my V5's built in speakers, then everything was fine.
The culprit was DIRECTSOUND. I first discovered this when I went into Winamp's options, and disabled DirectSound. Bingo: Music through my surround sound speakers!
Goto Start > Run > type in DXDIAG. When I clicked on the SOUND tab and tried running the Test Directsound, there should be an error message in the message box. I tried sliding the slider to the left by one setting, each time I got another error. Until I reduced all the way to NO ACCELERATION. Boom, the DirectSound Test played all the samples perfectly. I then went back to Windows Mediaplayer. Ta da! Crystal Clear MP3 music playing through my home theatre setup!! :D
So just an FYI for anyone else who's run into a similar problem.