[Closed] Multiple copies of the same Cust. Attrib apearing on one object

I have a cust attribute which I attach to all the objects in my scene. The following script lives in my startup folder:

 
 myCustAttrib = attributes userAttribs
 (
 	parameters UserParam
 	(
 		myCustomProperty type:#integer
 	) 
 )
 
 
 fn addAttrib node =
(
	if isProperty node "myCustomProperty" == false do
		custAttributes.add node myCustAttrib
)

callbacks.addScript #nodeCreated "addAttrib(callbacks.notificationParam())"
 

Somehow multiple copies of this attribute start apearing on the same object. In one case one object had 400 copies and the scene would crash everytime the object was selected.
Does anyone have any idea’s about what may cause this? … Is there a better way to automatically attach a custom attribute?

Thanks in advance!!