Is it one of your game or application that changes the speaker setting instead of your OS. Probably that one of your application changes it then when you return to windows, it remain changed. I remember that the game sacrifice changed my speaker setting everytime I run that game. Maybe you want to check it...
Taking a wild stab here..
I noticed your mobo comes with a sound option, same as mine. I don't have a sound card so I'm not sure how XP handles this, but have you disabled the sound from the mobo and set the Audigy as the default sound option?
Yes I have disabled the onboard sound. I think WinXP is not saving my settings in general. I tend to set my font size for Explorer at "smaller" by going view/text size/smaller. It always reverts back to medium size.