my company has bought 3 T61s. all have this "issue", even the newest one right out of the box.
device manager shows 2 instances of 965 Express Chipset Family display adapters.
it also shows 2 ThinkPad Display 1680x1050 devices.
it also shows 5 (!) Default Monitor devices. when i connect my Dell 22" widescreen LCD, 2 of the Default Monitor devices turn into Plug and Play Monitor devices.
so i have 5 monitors and 2 display adapters. this does not make sense to me...