Help my tween stop stuttering!

OK, I’m fairly new to AS3 and I’m trying to make a pretty complicated (for me) set of behaviors. You can see what I’m trying to do here:

The Main class sets up the crosshair, the navigation, the color bars that randomly roam the stage, and the 3 words that float around. The idea is that when you hover over a word, the color bars split apart like a curtain and two random pictures appear. Then, when you roll off the word, the pictures disappear and the color bars start roaming again.

I’ve got the color bars, the floating words, and the curtain split working great. My problem is bringing in the pictures. For whatever reason, 60 to 70% of the time the tween stops before it is complete. I think it has something to do with the fact that I’ve got a hover on a piece of text, and the mouse sometimes slips into the empty spaces between the letters, but even when I put a semi-transparent rectangle over the whole word to act as a hit area I got the same results.

The ZIP with all my classes is here: Again, I’m new to AS3 and OOP, so if you have suggestions on how I can improve my classes, I would appreciate that, too. Thanks!