FLASH 8 PROBLEM: Graphics won't tween

Hi, and thanx for the previous help with my website everybody. I'm now having a little bit of a problem with Flash 8. I'm sure it's something simple that I'm over looking.

I have a flash movie that's already developed for my site and I'm adding some "Blinged-Out" text. I wanted to make the Diamond text SPARKLE.

So I created a nested animation inside the Diamond Text graphic and have a sparkle.png that I saved and imported into Flash 8, but everytime I try to tween the sparkles in and out the spark just disappears all together and is not in the animation anymore. The same problem happened with my graffiti effect. Is there something i'm NOT doing.