I called S&W again and asked about the mag catch problem. Apparently the mag catch is too short and is allowing the mag to drop with little or no pressure on the release button and also while firing. So maybe it wasn't me hitting the button on the recoil .... they're sending me new catches for both my pistols. Guess we'll find out next week when they get here!

Thanks for all the help... I was about to trade both my M&P's for Glocks!