xbee module failed

i have two xbee shields with with the 1mw xbee modules on top of two duemilenove. unfortunately the module failed and i do not know why. in fact the led on the shield stopped blinking. do you know about this problem? could someone advise me some procedure in order to prevent damaging the module in the future? thanks

Shields !!!

I was going to say that you are sending the full 5v to the Rx pin, but if its a xbee shield that should be controlled for you. Check that its getting 3.3v supply ?

I guess ike anything they can just fail without any reason.

If you programmed it somehow to go to sleep, you could ground pin 9 (to pin 10) and see if it wakes up. Other than that, do it while X-CTU is in charge and see if it responds.