[fmx] tween halts when color changed

I have a graphic (behaving as a movie) that has a motion tween. Color selector buttons let the user change the color (using setTransform) of this moving image.

BUT… as soon as one clicks a button to change the color, it stops moving (eveything else carries on moving though).

A good example of what happens is: picture a red car moving across the screen. A potencial buyer wants to see what the car will look like in yellow and as soon as they click the yellow button, the body work of the car becomes yellow and stops dead. The rest of the car carries on. Buyer not impressed and I loose the sale!!!

Any ideas?