Access 2000 bitching... "The field is too small to accept the amount of data you attempted to add"

I am getting a

"The field is too small to accept the amount of data you attempted to
add" postgresql error when attempting to enter data into the following
linked table in MS-Access. Nothing seems to be out of range. Any
ideas?:

CREATE TABLE tblpis_survey_receipt (
insertion SERIAL,
ppt_id INT4 NOT NULL,
date_received DATE NOT NULL,
staff_id INT4 NOT NULL,
survey_type INT2 NOT NULL,
is_blank BOOL NOT NULL,
birth_month INT2,
birth_year INT2,
check_ppt BOOL NOT NULL,
check_dob BOOL NOT NULL,
check_tracking BOOL NOT NULL,
date_inserted TIMESTAMP WITHOUT TIME ZONE NOT NULL,
date_modified TIMESTAMP WITHOUT TIME ZONE NOT NULL,
PRIMARY KEY (insertion)
);

Peter T. Bense - Teradata Certified Professional
(ptbense(at)gwm(dot)sc(dot)edu) - 803-777-9476
Database Administrator/Webmaster
Prevention Research Center
University of South Carolina