BUG #4364: type of "new.id" does not match that when preparing the plan

The following bug has been logged online:

Bug reference: 4364
Logged by: Alexander Kirpa
Email address: postgres(at)bilteks(dot)com
PostgreSQL version: 8.3.1
Operating system: FreeBSD 7.0
Description: type of "new.id" does not match that when preparing the
plan
Details:

After change column type from integer to smallint
trigger function generate next error
----------
2008-08-19 20:50:30 EEST 42945 ERROR: type of "new.id" does not match that
when preparing the plan
2008-08-19 20:50:30 EEST 42945 CONTEXT: PL/pgSQL function
"job_tf_after_update" line 3 at IF
2008-08-19 20:50:30 EEST 42945 STATEMENT: UPDATE job SET
processid=43057,job_starttime=now() WHERE id=2
----------- error line in trigger
IF NOT EQ(NEW.id,OLD.id) THEN
RAISE EXCEPTION 'UPDATE id NOT ALLOWED';
END IF;
-----------
Workaround: touch trigger function