psycopg2 not using appropriate type?

It seems when I use callproc(), psycopg2 isn't properly casting strings as
text or character varying.

For example:

values = [pid, 4, 4, 'bureau pitcher ama', 0, 130, row['report_dte'],
row['report_dte'], 1, 1, 1, None, None, 'published', row['report_dte']]
cur.callproc('header', values)

Yields:

psycopg2.ProgrammingError: function
basetek_scouting.insert_report_header(integer, integer, integer, unknown,
integer, integer, unknown, unknown, integer, integer, integer, unknown,
unknown, unknown, unknown) does not exist
LINE 1: SELECT * FROM header(509952,4.

First, the "bureau pitcher ama" is unknown instead of text/character, and
row["report_dte"] are all unknown, where they are date types in the
database, and datetime.date objects in python.

Any idea? Using python 2.6.5.

--
Wells Oliver
wellsoliver(at)gmail(dot)com