Odd problem with motion tweens

Hey everyone. :slight_smile: I’m having this odd problem with Flash MX that I’ve never had before with motion tweens involving fading symbols.

For example, I have a symbol which reads “hi”. On frame one, the alpha is set to 0 and on frame 30 the alpha is set to 100. I then added a motion tween. When I preview the movie, the text fades in and fades out. But when I test the movie, nothing happens. If I export the movie as a .swf file, nothing happens there either.

I’ve used this effect many times, but this is the first time I’ve never had it work properly. Any ideas as to why my motion tweens don’t work?