The 8.1 server doesn't work when issuing queries using the v2 protocol,
notably the isnull bitmask in the DataRow message is incorrect. I suspect
the problem is with this commit:
http://archives.postgresql.org/pgsql-committers/2005-03/msg00224.php
I've attached the tcpdump output from establishing a connection with the
JDBC driver using the V2 protocol to a 7.4 and an 8.1 server. In the 7.4
server after the 'D' message is c0 while 8.1 has 00 as the next byte.
Kris Jurka