db has disappeared from pg_database - Mailing list pgsql-admin

Hello.  Has anyone come across the above error?  I've been trying to
create a database as user 'postgres', which doesn't report any errors,
but when I try to psql into it I get the above error about it having
disappeared from pg_database.

I'm not sure what might be wrong and hope someone might have some input.

Thanks,
Steve