Pg_dumpall from different versions

If I try to use the pg_dumpall from a 7.3.3 server to dump data from a
7.0.2 server, I get the following error:

   pg_dumpall: query failed: ERROR:  OUTER JOIN is not yet supported

Then I tried just copying the pg_dumpall from the 7.0.2 server onto the
7.3.3 server and trying to use that binary instead, but I get this
error:

   psql: FATAL:  user "root" does not exist

What are my options for doing a dumpall from a 7.3.3 server to dump the
data from the 7.0.2 server?

--
Robert