Symbol Tweening?

Howdy.

I have a movieclip that plays on rollOver and that has several layers that are all supposed to resize (grow) during the tween.
The normal shapes do this just fine with shape tweening but the one layer that contains a symbol doesn’t. I found out by now that this is directly connected to the fact that I use setRGB on it to change it’s color (see post #3 on this thread)… any ideas how to solve it?

I tried everything from using motion tweening to making single keyframes of it- every time it looked okay in the timeline and the symbol resized accordingly… but when played back, it stays the same… why is that so? Flash bug? Or user error? ^^

Thanks!
~Marcel