I believe I have the problem solved. I talked to Meprolight and they said that the this has occurred before and the problem is that some of the slides didn't have the final milling operation on the slide and therefore the sight screw is a bit too large and actually pushes down on the barrel preventing it from going into battery. He said the only ways to fix it is to take a little bit off the head of the screw or mill a small area inside the slide where the screw goes. I think we are talking about only a couple thousants of an inch. So I touched the head of the screw to my buffing wheel with 320 grit and Presto!!
It now fits and goes into battery perfectly.
Thanks for for all the suggestions, you guys really did help me solve this. I have never seen or heard of this problem before but I guess it is out there and affects an unknown number of guns.