Smith & Wesson Liner Lock Folding Knife

I've had Smith & Wesson knives, before, and been very pleased with them, but have been severely disappointed with this particular model. My only complaint (and it could just be that the knife that I received was a lemon) is that the blade locking mechanism doesn't work, at all. When the blade is fully opened, the locking mechanism doesn't slide under the bottom of blade and I slight tap on the back end of the knife dislodged and closes it, making it extremely dangerous to use when poking or stabbing through anything.
Besides that, the knife is fine, but I could have purchased most any knife and gotten one with a decent-ish blade and clip. I expected better quality from Smith & Wesson, not a knife that was more likely to remove my fingers than successfully stabbing through a hot dog.