rotation of the movieClip changes width of him

i have a movieclip called char, and he has some others mcs in his inside as, for instance, char.la(his arm) that has another with name of char.la.ha(his hookarm).

When i'm rotating the char.la, his trajectory looks like a elipse due the growth of the arm, and this give my project a horrible looking.

code:

stage.addEventListener(Event.ENTER_FRAME, main);

function main(c:Event){

char.la.rotation++;

}

How can i solve that?