>It looks like Listserv is issuing an INSERT statement as oppose to an
>UPDATE statement which could possible mean that the SELECT FOR UPDATE
>statement prior to the INSERT (or the SELECT FOR UPDATE statement that
>verifies whether or not an email is already subscribed to a list) returns
>an empty recordset.

I agree that this seems to be the case. I suggest enabling tracing in the
ODBC driver to see what is happening. It is difficult to say more without
this information. As you can see from the logs, the sequence of SQL
statements is the same, except for the final one. That is, LISTSERV does
look for an existing record before deciding to use INSERT rather than
UPDATE. Presumably, there is a problem with this SELECT. I also wonder how
the columns referred in the SELECT are defined (type, length, etc).

There have not been any changes at all in the high-level DBMS code in 14.4,
but there were quite a few such changes in 14.3. So I suspect you would have
the same results with 14.3 if you tried it. Conversely, a site that does not
experience this problem with 14.3 is unlikely to get in trouble by
installing 14.4. I cannot promise anything since low-level database drivers
may have changed, but in principle there is no DBMS change in 14.4.

  Eric