Interesting...that happened to me with the B17 Special with the big copper rivets and chromed rails using a 27.0 Chorus seatpost on my X0-1 a number of years ago. A bit disconcerting, to put it mildly. I replaced that saddle (might still have it kicking around) with a black standard ladies model (which I sold to a list member because I didn't care for the width, so replaced with a brown standard men's width). In addition , using an excess of caution and not incidentally, based on aesthetics, I swapped out the old Campy SR single-bolt seatposts on my A/R and Road with Nitto's S83 2-bolt seatposts, reasoning that the 2 bolt design might relieve stress and prevent a recurrence. So far, so good even though my reasoning might be less than solid.