sometime, pgadmin3 don't display functions text

Hi, 
I just downloaded the release 1.0.0 for Debian.
I can open my database and browse the components tree.
But, for some functions, I don't get the function body in the right box.

For example, I get only this:

-- Function: public.aggiorna_costi()

-- DROP FUNCTION public.aggiorna_costi();

CREATE OR REPLACE FUNCTION public.aggiorna_costi()  RETURNS bool AS
''  LANGUAGE 'plpgsql' VOLATILE;

Obviously, the function body exists: I checked it using \df+ in psql.
This behavior happens only for some function (around 20% of cases), but 
I was not able to find any analogy between the functions going wrong.