I have some printers that when show problem and we have to replace, the MAC-to-IP mapping remains at core and even when deleting manually it doens't work. If we use a different IP address at same network it works perfectly. After a lot of time (believe about 4 hours that is the time those informations are holded at core) it works normally but never at first moment.
My Equipments: Core: 6506 and Edge: 4509.
Equipment that shows problem: Barcode Printer Toshiba SX5T-7S12-QQ.