debug error when giving mod status

was adding a couple of moderators to my forum tonight and all went well until i was on the second one, when i was granting her permissions, i got this error
any help would be appreciated <img>
Could not obtain moderator status
DEBUG MODE
SQL Error : 1064 You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near ') AND aa.group_id = ug.group_id AND aa.auth_mod = 1 GROUP BY ug.use' at line 3
SELECT ug.user_id, COUNT(auth_mod) AS is_auth_mod FROM phpbb_auth_access aa, phpbb_user_group ug WHERE ug.user_id IN () AND aa.group_id = ug.group_id AND aa.auth_mod = 1 GROUP BY ug.user_id
Line : 586
File : admin_ug_auth.php
any help would be appreciated <img>