I initially had some trouble getting my XBees up and running. The problem started with me accidentally ordering the series 1 XBee instead of the series 2, TWICE. Once from Amazon and then again from Sparkfun because the descriptions were confusing and poorly labeled.
Anyway, once I got the right XBees, they initially would not work very well. As it turned out, one of my pins had a COLD SOLDER. What a pain! Even after all that, I was getting communication errors with XCTU. I final figured out how to reset the XBee by pulling it out from the USB explorer, putting it back in, then hitting the “Restore” command in XCTU. After that, things went smoothly and I was chatting away like hyped-up valley girl.