| I've run into this before on my Laklands and non-Laklands. Ocassionally a spring or intonation adjustment screw will come loose somewhere over time, causing a buzz. Also, there can be minute movement of the saddles at times against one another, causing a buzz of that nature. Lastly, the way the string sits on the saddle at the break point can cause issues... if it's seated in just the right way, a roundwound can develop a buzz when plucked hard, right at the bridge. Check all the intonation screws... tighten them just enough so you know they're taut against the back of the bridge plate. If the buzz is still there, squeeze the bridge saddles of the E and G strings together to tighten up all the saddles accross the board, while plucking hard with the other hand. If the buzz goes away, you'll know it's a saddle movement issue. Solutions I've used are to cut a very small piece of felt into a round shape the size of the saddle, slip it between the offending saddle and then tune up. This adds a barrier between the saddles that can't be seen and will dampen vibrations. I've also done this on springs before. Felt is your friend in fixing weird buzzes in a lot of cases... I've fixed many a nut issue on basses in the past with a small piece of felt under the string in the nut groove to dampen the buzz if there's something going on. Lastly, check all the screws holding the bridge onto the body. They can come loose ever so slightly over time... after all, these things vibrate!
As an aside, even the most well set-up bass (and bridges specifically), will buzz when plucked VERY hard. Under normal amplified conditions it may not even be an issue. | 
