PostgreSQL 9.0b1 - Error when checking table sizes

This probably isn't a legitimate bug, but as a precaution....

I'm running the following command against PostgreSQL 9.0 beta 1:

psql -U postgres -d test -c "select tablename,
pg_size_pretty(pg_table_size(tablename::regclass)) from pg_tables
order by tablename;"

And getting the following message:

ERROR: relation "sql_sizing" does not exist

It doesn't matter which database name I use. It doesn't have a
problem getting database sizes though. This is under Gentoo Linux x64
with 2.6.32 kernel.

I'm certain I've successfully listed table sizes in the database a
couple days ago.

Thanks

Thom