If you are trying to scan an inventory item into a purchase order or invoice and the scanned numbers seem to delay coming into the field consider networking configuration.
One client had this problem and has determined that his current network layout goes through multiple switches and routers which are relatively distant from the workstation. This seems to be the cause for the delay or hesistation of scanning at the PO.
He did a test using a hub and more direct connection. It is working much faster. He will now redesign his network layout.