At a customer site today to check caller ID issue. They have 7 lines with caller ID from co. 3 lines (801,803, and 812) are not showing caller ID on the phones. I let the calls ring multiple times and all that is displayed is trunk number. If I swap lines with no caller ID to line ports that shows caller ID still no caller ID. Trouble follows the line not the port. For testing purposes i moved the lines to 800 gs/ls-id board with open ports and reprogrammed, still did not display caller ID. I have a caller ID box for testing and when I plug the lines with no ID on the system into the caller ID box, caller ID is shown??????? Any help would be appreciated. Thanks in advance!