I have problems with two XBee modules.
The first one is XBP24-Z7WIT-005 revB and the second one is XBP24-BWIT-004 revD. Using X-CTU I could not communicate with neither of them.
With other two modules (XBP24-Z7UIT-004J revE and XBP24-BCIT-004 revD) and the same hardware I have no problems -- communication and firmware upload is working just fine.
I could not figure out why the first two modules do not work. If anyone has a clue I would appreciate the help.