If the POH/STC states 3200#, and you are at 3199#, I wouldn't think twice about it.
Common sense (and a little business know-how) tells me that the engineers, test pilots, mechanics, insurance underwriters, attorneys, and FAA have built in some "buffer" room into that 3200#. I wouldn't try it, but I guarantee it isn't a happy accident that the load factor limit just so happens to be at 3200# exact. While not necessarily legal, I don't think that if you loaded the plane to 3201# it would spontaneously combust and mass hysteria and catastrophe would ensue. Now where the breaking points, stress points, or whatever else could happen truly is, only the engineers and FAA knows. I certainly don't want to be a test pilot and find out for myself. I trust their numbers are very "safe" and conservative numbers.
-Andrew