Problems connecting to the database -_mdfd_getrelnfd: cannot open relation pg_type: Permission denied

I am running into problems when attempting to connect to the database.
The server(version 7.3.2-1PGDG) starts just fine.

Running to some permission problems:

psql dbuser
ERROR:  _mdfd_getrelnfd: cannot open relation pg_type: Permission denied
psql: ERROR:  _mdfd_getrelnfd: cannot open relation pg_type: Permission
denied
LOG:  pq_recvbuf: recv() failed: Connection reset by peer

dbuser owns all the tables and the database.
This used to work fine before.

I am new to postgres, I couldn't find any other post which was
similar.

Thank you,

Uma.