I have a problem with the XBee's that I have: http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail&name=602-1180-ND
Right now, I have one XBee as an End Device, and the other as a Coordinator. The Coordinator currently cannot transmit any messages, but can receive them. The End Device sends and receives messages.
I have configured both XBee's using X-CTU and both have Destination High/Low settings to connect to all transceivers with the same Pan ID. They are also both connected using an Adapter Kit from Adafruit and have an FTDI cable going to a computer.