Can't get arduino uno and xbee to communicate!?

Hi My friend and I can't get the x-ctu program to work corretly. Every time we press the Test/Query buttom, this appers:

Communicate with modem.. OK Modem type = Name unknown (ID = 5200) Modem firmware version = ?????????????????????????????????????????? Serial Number = ??????????????????????????????????????????????????????

Are there someone who is familiar with the x-ctu program who can help us?