After installing Inventory 220.127.116.11 about 1/3 of the computers I put the agent on are reporting '(Waiting for Agent)' in the Scan Status field. They seem to be stuck in that state. If I go to the target Agent page, it says the Status is 'unavailable', but I know the machine is on and connected to the LAN. I've tried rebooting the target computer, restarting Inventory, uninstalling the agent and reinstalling it. How do I troubleshoot this?