nodeRead: did not find '}' at end of plan node

Dear All:
Im running psql (PostgreSQL) 7.3.2 here and since some weeks Im getting this error when trying to dump all databases (to upgrade to pg 7.4.1)

\connect XXX
pg_dump: SQL command failed
pg_dump: Error message from server: ERROR: nodeRead: did not find '}' at end of plan node
pg_dump: The command was: select (select usename from pg_user where usesysid = datdba) as dba, encoding, datpath from pg_database where datname = 'emepe3'
pg_dumpall: pg_dump failed on emepe3, exiting

I've found some pages in google but I couldn't find the answer.

Thanks in advance!

--
you can find my public PGP/GPG key at http://www.n3rds.com.ar/files/martin_sarsale.key