I tested with general logging on, these parameters were being passed as '' instead from DM's "" to NULL in sql.
i.e.
WHERE ('dave' IS NULL OR ckey = 'dave') AND
(NULL IS NULL OR a_ckey = NULL) AND
('' IS NULL OR ip = INET_ATON('')) AND
('' IS NULL OR computerid = '')
Haven't checked if this is happening elsewhere.
67e4646d34