Hello,
It seems version 902 is a bit daunted ...
On http://jdbc.postgresql.org/download.html row 9.1 Build 902 column
JDBC 4 you can read: "9.1-903 JDBC 4", although the link is correct
(http://jdbc.postgresql.org/download/postgresql-9.1-902.jdbc4.jar).
Thanks,
Luis Flores