I had a problem a few years back on my SR post on my Marinoni: I used a little blue loctite on the mating surfaces of the seat clamp, and the problem never returned. If I had that post now, I would use beeswax, because it looks like it would do the same thing.
Mark Rosenberg San Diego, fresh back from doing 118 miles at the Tour de Tucson on his classic Allin touring bike with the cool JB paint job and Brooks saddle