time out waiting for data

After installing the X-CTU, i connected base to my lappie using USB (XBee) with the U.L antenna. Then i connected the red loopback db9 to another remote. I then open the X-CTU, setting all by default, baud rate 9600, Flow control NONE, Data bits 8, Parity NONE, Stop bits 1. My AT is 1000ms and i run the test, i found all i get is Timeout waiting for data. Communication with the modem is OK, Modem type = XB24, Modem firmware is 10A5. May i know what is the problem? I am really a newbie in XBee. Thanks for helping.