While performing db dump (from postgresql 8.4), pgAdmin stores CREATE
LANGUAGE in following way:
CREATE OR REPLACE PROCEDURAL LANGUAGE plpgsql;
This syntax is not compatible with postgresql 8.4
OR REPLACE has been added in v9.0
Reference
http://www.postgresql.org/docs/8.4/static/sql-createlanguage.html
Also "PROCEDURAL" keyword does nothing and may be skipped.
tested with pgAdmin 1.14.0, 1.14.2, 1.14.3
on postgresql 8.4