arduino configure xbee module

Hi,
i'm trying to configure an xbee series 2 module under mac.
I have an arduino uno and I'd like to use it to configure the module, so I set the jumper on xbee shield on USB position (both of them), I removed the atmega from arduino, download coolterm, connected arduino with xbee shield and xbee module to usb port.
I lunched coolterm (anebled local echo option) and I can connect via serial port to the board but when i digit (I waited 2sec before digit)
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i dont get any OK message (I did not typed "return" botton). Any hint?