The change is indeed for integrity (not security) reasons. If you do a
GET with the NOLOCK option, LISTSERV is free to continue modifying the
list. If you then do a PUT, changes made by LISTSERV will be lost, and
noone will be notified. So, when you use NOLOCK, LISTSERV doesn't add the
PUT line. When you do NOLOCK *and* HEADER, meaning you will only modify
the header, LISTSERV will write the PUT line in 1.8b but this is not the
case in the base 1.8a. UBVM is running an advance release of some of the
1.8b changes and in this respect behaves like 1.8b.
Eric