Did you try changing the volume from master to wave in settings 1? (for test porpuses)
Also it may be a setting in the SC itself. (soft)
What skin are you using?
ran into a weird little problem. Just installed a creative audigy sound card and now in frodoplayer the volume and mute buttons dont have any impact on sound. It shows it going up or down or on mute in the skin but it doesnt affect the windows master volume.
btw i only listened for a couple minutes but the audigy eliminated the slight hiss/crackle the onboard soundcard has been doing since the beginning of the install Those sounds would used to drive me nuts on trips cuz only i knew it was there and no one else picked it up. Alls left is shut down pop.
well the pc froze a couple times on the reboot so i went back to the onboard sound card and all was well...next day i tried the Audigy once again and this time it worked and is working perfectly fine with frodoplayer btw i was using the brightlife skin.
Not sure what was causing the problem, but its working now.