Xbee on relayduino kta-223 (works on arduino uno without problems)

Thank you for your response, I checked the voltage, it is at 3.28
The associate led is blinking but only for 3-5 seconds on restart. After that it turns off and stays off. However when I put the shield on the arduino uno the led keeps blinking constantly.
Anyone any suggestion how to get it to work on the relayduino?