Does the FTDI show up in the Windows Hardware Manger when its plugged in?
Are the connects to/from the FTDI to the breakout correct?
Is the voltage on the XBee good? 3.3V
Which XBee modules, Series 1 or series 2? Which protocol, 802.15.4, ZB, ZNET, Digimesh?
Do you try other baud rates in X-CTU?
How about API mode?