Having an issue with an SR861 booklet finisher. It is connected to a 2075. Occasionally when either powered up or when the finisher door is opened at idle it will throw a jam. If I try to reset it a couple of times it throws a SC730 (staple error). I have swapped staple unit (not the booklet staplers) cleaned all sensors (even swapped a few). I have updated the firmware. Any ideas as to what to look for next?