Hardcoded Tweens Sticking when Targeted in AS3

I have an animation of a human figure, where each body part is a separate movieclip.

The animations are constantly looping via keyframe tweening.

Once a certain button is pressed, the body parts (which contain different types of limbs) are targeted - each is sent to a different frame.

When this happens, the overall animation of that movieclip apparently freezes - though, through tracing the current frame, I can see the movieclip is still moving through its frames - it’s just not showing the animation onscreen. The parts stay in the position they were in at the moment the button was clicked, and the movieclips targeted.

Why is this happening? And, how can I get around it?

Thanks.