plpgsql overloading bug in 7.3.2 on OS X

I'm having trouble overloading functions in plpgsql using PostgreSQL
7.3.2 on OS X.

I have created two functions with the following declarations:

CREATE OR REPLACE FUNCTION set_entity_type(BIGINT,TEXT) RETURNS BOOLEAN
AS ' ...
CREATE OR REPLACE FUNCTION set_entity_type(BIGINT,BIGINT) RETURNS
BOOLEAN AS ' ...

But it is not using the correct function:
SELECT set_entity_type(88,'Category');
ERROR: pg_atoi: error in "Category": can't parse "Category"

swm on #postgresql suggested enforcing the datatype in the function
call, as in 'Category'::text . This worked fine, but as I understand
it, this is still a bug.

Thanks!