We have a IP406 V2 control unit with a DCPx30 V2 hooked up via expansion port. When we hook up phones through the expansion unit, the displays on them do not work. They're just all dark. However, if I push a button (menu) I can briefly see the display, but it goes back to dark within a second. Also, when the phone is first plugged into a port, I can see the date/time on the display for a split second before they go dark. The manager software see the phones. The phones all function as they should. We can send/receive calls with them. The buttons and LEDs all work as they should... it's just the display. We've tried numerous phones 6424D+, 6408D+, 4424D+ ... they all do the same thing. When they're plugged directly into the main unit via one of the 8 built in digital station ports, the displays all work as they should. The cable between the main unit and the expansion IS an actual avaya OEM cable, not an ethernet cord. Both the main unit and the expansion have been upgraded to the latest software via the Manager software. This has me completely stumped. Has anybody else ever experienced this? We also have a V1 30 digital port unit that was tried and the phones still had the same issue.