DBVisualizer Null Pointer Exception

Howdy, I'm trying to evaluate DbVisualizer but have run into some
trouble with the Object Browser. I am using Red Hat 7.2 and the JVM
supplied with DbVisualizer (jdk 1.3). I am connecting to a postgres 7.2
database. I am able to get a connection ok and can execute queries with
no trouble, I can also view the database info, data types and table
types with no problems. However, when I click the references tab to view
the fancy object graph, i get the following error:

[DEBUG] DB=myserver::mydb Cat=null Sch=null
Exception occured during event dispatching:
java.lang.NullPointerException
    at
    org.postgresql.jdbc2.DatabaseMetaData.getTables(DatabaseMetaData.java:1707)
    at se.pureit.dbvis.Selector.getTablesFor(Selector.java:679)
    etc...

I've tried switching JDBC drivers (jdbc7.1-1.2.jar, jdbc7.1-1.3.jar,
pgjdbc2.jar, and devpgjdbc2.jar) but all produce the Null Pointer. The
mailing list archives seem to indicate that people have gotten it
working, but nothing saying conclusively that the graphing would work or
that it works with my relevant setup. Is there something else that could
be causing a problem, or perhaps I need a newer JDBC driver (though I
don't think there is one)?

Thanks in advance,

Robert Treat