Stop Nan displaying

I have a mp3 player which displays Nan in the time text and did a search to see why. I then read a tutorial by Kenny Belew which says…

If you have ever seen a preloader reporting “NaN” (Not a Number), it may be because the ActionScript is attempting to calculate data that is not yet available.

My player works in when published to Flash Player 6 but not 8.

Anyone else have problems like this?
Thx

CB