Garbage collection frustration!

Hey guys,

I have a project which creates 9 gallery frames. Each frame is a simple square movieclip with an alpha of 0. When all 9 movieclips have been created, I am attempting to tween them in using TweenLite or the Flash tween engine.

The problem comes completely randomly, my tween function cycles through each of the 9 movieclips and fades it to 1… but occasionally when I run the movie, the first movieclip stays at 0! This happens completely randomly and after some research I believe it is a garbage collection issue? Can anyone suggest how I can fix it?