Being new here I've been surfing around this great forum, but I now have a concern about my M&P 40. I bought mine used, S&W said their warranty does not apply to used guns. I've dealt with them before, they are always fair. I've been reading about all the problems the early models had. Mine starts with MPB and its in the 5000 range as far as the numbers go. Is this an early model with all the problems? I really like the feel and looks of this gun. I shot my friends before I made my purchase, but, his was a newer model. I haven't had a chance to shoot mine yet. Any advice would be nice. Thank you, Frank.