Unable to dump database using pg_dump

[Adam Dear <adear@xxxxxxxx>]

I am migrating to a new server.  I am trying to get a dump of my 
database to import into postgres 8.1.11 on my new server.  When I run 
the pg_dump commmand:

pg_dump --clean --file=madison.sql --schema=public -U madisoncounty 
madisoncounty

I get this message:

pg_dump: query to obtain list of schemas failed: ERROR:  more than one 
row returned by a subquery used as an expression

I'm pretty new to postgres, and I'm not sure how to debug / fix this 
issue.  I did a VACUUM FULL on the server before I tried to do the dump.