I don't know for sure this is a shot in the dark, but does the "striker" that the latch "latches" to have a plastic sleeve like doors and tail gates? If so this may be your problem. The plastic broke off the doors on my '95 and the tailgate of my '94 causing the same affect. If thats your problem the whole peice has to be replaced...no way to just replace the plastic :banghead
You'd think so, most definitely. However, this happened to my roomie's Mustang tailgate latch, and I found a pretty acceptable fix. Go to your hardware store, and look in the bolt/nut/etc bins. You'll evetually find some nylon sleeves/spacers. Get one that has a close diameter. Slit this lengthwise on one side, pull it open with your fingers, and clip it over the offending post. Secure with a couple drops of super glue. It replaces the plastic perfectly. Been going strong for well over a year now.