Deliveries that get locked in shipments in OTM

Does anyone ever have an issue where you cannot unassign a delivery or deliveries from a shipment in OTM? We have an issue where deliveries will get locked up it won't let you do anything with the delivery. You can unassign or replan.

We also have an issue at times where a shipment will show, for example, 16 deliveries in it at the shipment header, but when you query all  the deliveries by shipment #, it might show one less delivery, in this case 15.  So, the counter is off somehow. In this case it's even worse, because you can't do anything with any of the deliveries, other than delete them from OTM, and have our sales re-assign new deliveries to come back to OTM.