There's no extra programming other that to assign the lines to DXD, set the number of rings, and assign a DXD button to Ext. 10.
If it is not picking up extension numbers at times, you may have a bad touch tone receiver on one of your cards. Diffulcult to determine on an ACS. You could remove all the cards except the ACS and test, then add back cards one at a time to find the faulty one.