'with' statment not working in tornado

Transaction isn't rolling back in case of error. Please check the file attached.

how to reprocude error:

run the tornado instance;
access localhost:8080/signup/create;
make a POST request with an empty value for one of the dates;

The exception raised will be:
psycopg2.DataError: invalid input syntax for type date

Error after trying to access the same page:
psycopg2.InternalError: current transaction is aborted, commands ignored until end of transaction block

python version = 3.4.1
psycopg2 version = 2.5.3
tornado version = 4.0

table users:
Table "public.users" Column | Type | Modifiers ---------------+--------------------------+----------- user_id | integer | first_name | character varying(20) | last_name | character varying(40) | nick_name | character varying(20) | gender | character(1) | birth_date | date | not null country_id | character(2) | created_date | timestamp with time zone | not null news | boolean | last_mod_date | timestamp with time zone | not null Check constraints:
"users_gender_check" CHECK (gender = ANY (ARRAY['m'::bpchar, 'f'::bpchar])) Foreign-key constraints:
"users_country_id_fkey" FOREIGN KEY (country_id) REFERENCES countries(country_id) "users_user_id_fkey" FOREIGN KEY (user_id) REFERENCES credentials(user_id) Disabled triggers:
update_users_date AFTER UPDATE ON users FOR EACH ROW EXECUTE PROCEDURE update_mod_date()