mysterous sound problem

I suddenly have sound problems.

I noticed the other day while playing nhl2004 that while some sounds were fine, others were missing. I thought this was related the that application, but the problem exists in all sound using applications.

some sounds play fine while others don't play.

normally I would update driver, check for typical sound probs ect, but I'v done absolutly nothing in the last 2 days other than routine computer usage. (2 days ago sound was fine). no driver updates, software installs, ect... I am the only user.

what on earth could this be,

i'v tried updating driver, directX, ect...
I'm stumpd.

 

thnx,

mp3's, wmv's, and other media seem to work fine.

but when I do the 'test directsound' in dxdiag, there is no sound. (it is very faint).

in some apps, some sounds just seem to be missing (or very faint)
ie: background music works but no soundFX.

seems to be every app that uses directsound

also, it only applies to this user account, if I log onto another account, everything is fine.

I know I could just use the other account to run the app, but userdata would be lost.

all volume controls are fine.