remote device type unknown?

So I have a small network set up on my test bench.
It has 2 x XB3-24Z8C modules and an old Maxstream XBee Module.
They are all attached with serial cables to various PCs and Macs, each has XCTU running, so that I can see the devices etc.

In the network map screen on each PC the local device’s type is shown properly but the remote devices all show as “?”
Is this just a quirk of XCTU or is there something I need to do to allow the “type” of each remote device to be discovered properly?

There’s a screen shot here that illustrates what I mean:
http://www.kennymillar.co.uk/xctu.png