I have to agree with this post. I've ridden bikes all my life and have never had this problem. Something is up with the chainrings and/or chain. It would take a very, very non-robust design for a problem like this to be caused by lube. I know how to ride, I know how to shift, I know how to maintain a bike. This problem has occurred on normal, as well as the most gentle of shifts.
Why can't the chainrings be out-of-spec? Any number of factors could cause parts to be made out-of-tolerance. It happens all the time. I think these "brand-new" chainrings are, for some reason, acting like very old, highly worn chainrings. I ain't no Sheldon Brown, but that is my opinion. I would love to get the chainrings and a blueprint in front of me. The fact that it has happened on two identical bikes that almost had to have come off the same assembly line during the same run of the product makes me think they had a shipment of bad chainrings during that assembly operation. I got a call today that the LBS is finished with the bike. They put on a new crankset. I am going to pick it up tomorrow and hit the trails.