I have used 4 AC's since I bought my PowerBook and they always seem to be weak at the end connector and end up almost catching fire after I neglect to buy a new one when I see it is on its last leg (now its just sparks but I am cheap) and I don't know what I can do, the fourth one just died, and I have no notebook now, so I am in real trouble, is this a common thing? Has anyone else had this problem?