Rotate circle on its own place

H folks,

i got a circle inside a mc (116x116 px) and i want it to rotate continuous…
if i do it in flash itself it works great the circle rotates nice on its own axis(tween) , but if i try it with actionscript the circle gets of its place and makes a big rotation


onClipEvent (enterFrame) 
	{ 
	this._rotation+=1; 
 

can someone explain ?

Thanx