I am saying that we do not know this to be a fact. The fact is, if you are at all worried about it, don't do it. As I stated in an earlier message, we do know that there can be a problem with bent battery contacts and this shows up after changing batteries whether or not you use the def command. >>> n8kl@xxxxxxxxxxxxx Tuesday, December 13, 2005 10:33:36 AM >>> Are you saying that the statement that pushing D E and F could crash newer units made a few days ago by either Rob or Pam is not true? We know that several units including mine had to be sent back for repair immediately after changing batteries.