I have a HP LaserJet 4050n on my network which randomly keeps displaying the paper jam message 13.1. I have gone through two full maintence kits in the past 3 months. The number of pages printed since I replaced the maintenance kit is 4,586. Yet the problem keeps happening. I have made sure there is no paper jammed any where in the printer. I have taken the printer apart to make sure of this. The paper tray is not over filled. Does anyone have any suggestions. This happens about 3 to 4 times a week.