Christopher Browne <cbbrowne(at)acm(dot)org> writes:
> The problem is likely that the "old tuples" are in some database not
> being vacuumed. template1 is a likely candidate; do a plain VACUUM on
> that and the message may go away.
It's not really necessary to guess about which database(s) are
triggering the message: a quick look in pg_database will tell you.
See TFM:
http://www.postgresql.org/docs/8.0/static/maintenance.html#VACUUM-FOR-WRAPAROUND
regards, tom lane