In two of our offices, we have 3660 MB-2FE routers. For line backups, we got a NM-2W module to place in the 4th bay, and in it put 2 WIC-1B-U cards (BRI ports with built in NT1s). The problem in both cases is that the router shows both BRI interfaces as 4/0, instead of 4/0 and 4/1. So far, Cisco has been useless for resolving this problem. Their recommendations have been to install new IOS versions that will work properly with the hardware, but we've now tried every version they could recommend to us: 12.0.7, 12.0.7XK1, 12.1.1T, 12.1.2T, and 12.1.4. Has anyone ever run into this problem, and if so, does anyone know how to resolve it?