S&W integral trigger lock failures
They're being discussed at the Smith & Wesson Forum. Quite a few reported -- trigger lock engaging under recoil, if dropped, etc..
Link via Xavier's Thoughts, reporting his own gun lockup.
Hat tip to reader John M. Maraldo, who adds: "puts me in mind of the differing attitudes gunnies and gunphobes have as to safety. Ask a gunny what safety is and they'll relate the rules of safe handling and safe shooting. Ask them what safe design is and they'll tell you it is a design that makes the gun shoot when the trigger is pulled, but not when the trigger is not pulled. Ask gunphobes what safe design is and they'll tell you it is a design which makes the gun unlikely or difficult."