Just picked-up my new M&P shield 9mm the other day.Was going through the field stripping instructions, got to the part where you lower the sear deactivation lever.I pushed the lever down and it fell right out the bottom of the mag well.I started searching the Internet for some way to put it back in.Called Smith&Wesson,they sent me a label to send it back, time,2or3 weeks to get fixed and back to me.I found this web site,you guys answered a lot of questions for me.I saw where S&W left a pin out of the spring that holds the lever.Armed with the information learned here, I removed the spring,put it and the lever in the box and the pistol works fine without it. I just use the trigger to remove the slide.