Please help! I've never had this problem before....so I don't know why this started.
I've been recording V/O and saving to .wav files for a long time.
Yesterday, everything changed.
Now, when I edit the files, they sound just fine.
But when I close them, then open them again, they sound like crap. My voice is distorted and sounds tinny. 
I've upgraded to the latest version of WavePad...but I'm sooo screwed.
My client needs these files tomorrow.
Suggestions?
Never mind....I'd delete this post....but can't figure out how to do that.
The answer to my question: I figured it out.
Sample Rate.
The Sample Rate was re-configured when I downloaded a fix.
All is working just fine now.