Xbee working??

Hi all
i am using Xbee s2 & X-ctu Version 5.2.7.5
initially while reading its modem parameter and firmware from X-CTU software it was showing modem name and its function-set when i tried to change the function set, then onwords its not writing to xbee and reading from xbee
so that
i have tried to re-flash but its not responding for those commands which is mentioned in the below link
http://www.digi.com/wiki/developer/index.php/Bootloader_to_force_XBee_reflash

can anybody tell me where is the problem? or my xbee is damaged?

Have you tried the techniques mentioned in the FAQs under XBee 802.15.4?