Reportedly it often does, wrecking it. There are some tips at the Dahon forums how to fix this.
Well, I'm not sure it's all that often but the fix is simple nevertheless. If you don't need the pump, you can change out the post as well as the seat. For me, I haven't had the thing long enough, but I'm being careful how I set it down folded - don't want to shear those nubs off, you know.