Thanks Ted and Billy. I have been taking that stand, Billy. Let the electrician put it on his letterhead that it's an acceptable situation. I have been Googling for some info and I just read on a forum chat room from 1999 a statement from an engineer at Square D on this subject. He stated that you should only use Square D breakers in their panel( as printed) and that Square D will take the position that the liability for the panel has been voided. I still would like to know if there is anything in the NEC or some other authority about this. I just don't understand why in the hell it is so hard for electricians or do-it-yourselfers to follow recommendations and warnings by manufacturers? Thanks again for your replies.