Sound recorder in Vista records but does not play

I have recorded songs using Vista sound recorder and they have played back fine and still do.

When I try to record now it looks like it's works, the bar moves, window media players shows all the graphics like it
plays but no sound. Itunes won't play it back either, the bar moves like it's playing but no sound.

All music and window sounds work fine.

Would appreciate some help.

Thanks

I'm wondering if you had the volume set too low during the recording phase. Since music and the Windows sounds play, it indicates the speakers are working.