problems upgrading

We were running postgresql 6.4 on a Linux RedHat 6.0 Intel machine. Someone
decided to upgrade the version to 6.5.3 , and went ahead and just grabbed
the rpms and installed them, not knowing you had to dump the databases.  The
system ran for about a week before someone discovered why we were having
problems.

When we went to run the dump according to the README.rpm, we got:

postgres@engine pgsql]$ cd /usr/lib/pgsql/backup/
[postgres@engine backup]$ postgresql-dump -t db.bak -p
/usr/lib/pgsql/backup/old -d
Connection to database 'magazine' failed.
pqReadData() -- backend closed the channel unexpectedly.
        This probably means the backend terminated abnormally before or
while processing the request.

Can this be fixed?  It is very urgent, as this our main development
machine....

--
Martha Greenberg
marthag@vcix.com
System Administrator
Virtual Communities Israel Ltd.
Phone: +972-2-568-9100
Toll Free from USA: 1-888-472-7635
Global Fax: 1-212-214-0860; Israel Fax: +972-2-568-9111