Fatal error in some cases when purchasing an enrollment to activate it

1) Create parent with a child. Add enrollment bundle fields to parent.
2) Enroll in the child (not the parent!)
3) Purchase the parent (make sure order is complete).
4) Error.

PDOException: SQLSTATE[23000]: Integrity constraint violation: 1062 Duplicate entry '670' for key 'PRIMARY': INSERT INTO {course_enrollment} (eid, nid, uid, enrollmenttype, status, created, type) 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] => 670 [:db_insert_placeholder_1] => 995 [:db_insert_placeholder_2] => 1 [:db_insert_placeholder_3] => ubercart [:db_insert_placeholder_4] => 1 [:db_insert_placeholder_5] => 1446135826 [:db_insert_placeholder_6] => enrollment_bundle_required_ ) in drupal_write_record() (line 7333 of /vagrant/www/ethos7/includes/common.inc).