Has anybody had their Glock 21 sf frame swap(Pictany rail)out? I took mine to Glock on 1-24-11 and dropped it off because the ambidextrous magazine release would get stuck when pressed in. The tech informed me that I would need a new frame and it would take a couple of weeks. On the new frame the Pictany rail would be gone, which was fine with me. I received it today through fedex and I noticed that the serial number on the frame does not match the slide or the barrel(my barrel and slide are the same ones i dropped off). Should I be concerned?