PDOException with Decounter

I'm getting this error sometimes:
PDOException: SQLSTATE[HY000]: General error: 1366 Incorrect integer value: 'daycount - 1' for column 'daycount' at row 1: UPDATE {node_counter} SET daycount=:db_update_placeholder_0, totalcount=:db_update_placeholder_1 WHERE (nid = :db_condition_placeholder_0) ; Array ( [:db_update_placeholder_0] => daycount - 1 [:db_update_placeholder_1] => totalcount - 1 [:db_condition_placeholder_0] => 37 ) in decounter_exit() (Zeile 73 von /var/www/html/sites/all/modules/decounter/decounter.module).