Unable to create or drop plpgsql

Hi everyone,

This is my first post to this group, so please be kind.

My database used to have support for plpgsql, that is I used the createlang
command line tool to add the language to the database and then added
functions, and they worked. Since then I have moved the database to a new
machine and a new directory (two separate moves). Now I can't drop the
language nor create it! Here is the output when I try to run the createlang
and droplang commands.

[jason(at)user-44 jason]$ createlang plpgsql esi
ERROR: function plpgsql_call_handler already exists with same argument
types
createlang: language installation failed
[jason(at)user-44 jason]$
[jason(at)user-44 jason]$ droplang plpgsql esi
droplang: language "plpgsql" is not installed in database esi
[jason(at)user-44 jason]$
[jason(at)user-44 jason]$ droplang --list esi
Procedural languages
Name | Trusted?
------+----------
(0 rows)

Any ideas on how to get plpgsql back into my database?

Thanks,
Jason Underdown