Have had the same problem several times. Taking it off the rack to eleminate all movement during transport helped but doesn't correct the problem completely. Ours has some hours on it now and another problem is that the attachment doesn't stay in place. Believe it to be wear (either the attachment shaft or the collar which tightens down onto the shaft).
"There is a class of people men, women and children, who must be killed or banished before you can hope for peace and order." William Sherman