1. Do you add the following?
ZDO_RegisterForZDOMsg( zclGateway_TaskID, NWK_addr_rsp );
2. byte order, little endian?
uint8 pDestination[] =[0x00,0x12,0x4B,0x00,0x04,0x3E,0xCB,0x41];
Have you checked this thread with your own code?
http://e2e.ti.com/support/wireless_connectivity/zigbee_6lowpan_802-15-4_mac/f/158/t/399413#pi239031348=1
// Include these two lines when generating a .hex file for banked code model:
-M(CODE)[(_CODEBANK_START+_FIRST_BANK_ADDR)-(_CODEBANK_END+_FIRST_BANK_ADDR)]*\
_NR_OF_BANKS+_FIRST_BANK_ADDR=0x8000