I was wondering if anyone else had experienced this problem. I installed a 2nd PRI (2 separate cards...one in slot a and one in slot b) in a 406 v1 and upgraded it to the latest 3.1 software. The PRI was taking slips approximately every 17 seconds or so. Slips would go away if one circuit was disconnected. It was resolved by setting the clock quality on one of the loops to network and the other to unsuitable. Something about not being able to clock on 2 separate circuits. Just a question to see if I should have seen this somewhere in the docs or if there is any more info on this topic.