Stopping, playing, getting info of an external .swf animation

programming flash
1

Hello!

I have an external .swf lib that I load using Loader class. I can get the content of it (images, text) using:

new (loader.contentLoaderInfo.applicationDomain.getDefinition(symbol) as Class)();

Then I use it to load a .swf (that I generated using Flash CS3 trial) inside that .swf lib:

var mc:MovieClip = new (loader.contentLoaderInfo.applicationDomain.getDefinition(symbol) as Class)();

I use addChild(mc) and the animation is displayed! So far so good, but the gotoAndStop, gotoAndPlay, stop and play, getting totalFrames, functions simply does not works!!!

What is wrong?
Thank you!