I have a 2600 that wont detect aN NM-2w modual. It has IOS 12.0(7)T2, the Cisco site says 12.0(7)XK is needed for NM-2w. Im not sure if 12.0(7)T2 is an earlier or later release than 12.0(7)XK. Should I upgrade IOS or look for another problem? Thanks James