There are several discussions in the forum, especially http://forum.mikrotik.com/t/not-responding-f-k-a-sa-query-timeout/168864/1 As far as I know, there is no simple solution - or even a solution at all to this problem until today. Especially in a church setting, where many different and unknown wireless clients are in use. However, maybe just post your wifi configuration here as an export. Probably someone here has some useful tips how to reach broader compatibility.