Jeff,
The system is running, so it is already using PG.
Since I have PG7.1 for and older site, and I am now using 7.2 to test ACS 4.6, I put PG7.2 in ad different port.
I set up the nsd-conf files
set pgport 5433
ns_param pgport $pgport
and
ns_param datasource localhost:${pgport}:${db_name}
for each of the DB pools.
Could it be that there is a call in the RP or somewhere else? that doesn't use the pgport parameter?