BUG In FLASH Timeline animation

Question

Hello All
I see very strange behevior in flash
I add to stage movie clip name body_mc
the body_mc contians inside of it two movie clips
mc_leg_left and mc_leg_right
each of the last two movieclips has animtion in the time line
with first frame with stop();
in the first frame of the main time line
i add the code
body_mc.addEventListener(MouseEvent.CLICK, onClick);
function onClick(e:MouseEvent=null):void
//body_mc.mc_leg_left .alpha = 0.5;  //<<=========== uncomment this line
body_mc.gotoAndPlay(1);
if you uncomment the line
you will see the mc_leg_left is really going to alpha 0.5
but its animation is stoped
while the other child movieclip mc_leg_right its animation is working
but if you leave the comment
the two legs are animating
is it a BUG in fash player or what?
have you see something like this?

Answer 1

Give it a try:
body_mc.addEventListener(MouseEvent.CLICK, onClick);
function onClick(e:MouseEvent):void
//body_mc.mc_leg_left .alpha = 0.5;  //<<=========== uncomment this line
body_mc.gotoAndPlay(1);