Using Transitons on Dynamic Clip

Attempting to use this code on a clip dynamically attached to the stage:


container_mc.bg_mc.attachMovie("lotus", "lotus_mc", 1);


mx.transitions.TransitionManager.start(lotus_mc, {type:mx.transitions.Zoom, direction:0, duration:1, easing:mx.transitions.easing.Bounce.easeOut, param1:empty, param2:empty});

The clip is loaded but the transition is ignored, should this be placed in an event?