Cannot make dates available (producing an error)

Hi
I installed the module and first it would not show up in the Shop Admin page but some other pointed me to the direrct URL for the module. Made the setting.
Added a room and made 500 rooms available.
Wanted to order - see the 2 mouth where all is red and click the " " and selected a month and saved it and got the following error:

Error messagePDOException: SQLSTATE[22003]: Numeric value out of range: 1264 Out of range value for column 'available' at row 1: INSERT INTO {hotel_booking_availability_calendars} (nid, calendar_dt, available, minimum_occupancy, minimum_stay, no_check_in, no_check_out) VALUES (:db_insert_placeholder_0, :db_insert_placeholder_1, :db_insert_placeholder_2, :db_insert_placeholder_3, :db_insert_placeholder_4, :db_insert_placeholder_5, :db_insert_placeholder_6); Array ( [:db_insert_placeholder_0] => 1 [:db_insert_placeholder_1] => 2011-04-01T00:00:00 [:db_insert_placeholder_2] => 500 [:db_insert_placeholder_3] => 0 [:db_insert_placeholder_4] => 0 [:db_insert_placeholder_5] => 0 [:db_insert_placeholder_6] => 0 ) in drupal_write_record() (line 6776 of /var/www/www.smsworking.dk/www/booking/includes/common.inc).

Please can anyone help me here?
I have tried to change the date format, changed the availability settings from 0 to 12 back to 0.
Nothing seems to help.