Three XBee 802.15.4 Series 1

Hello!
Xbee n° 1 receives data from Xbee n° 2 and Xbee n° 3 and passes them to a PC to be analyzed.
Xbee n° 2 sends data to Xbee n° 1 and to Xbee n° 3.
Xbee n° 3 receives data from Xbee n° 2 and sends data to Xbee n° 1.
I configured the modules according to the table below:

…n°1 …n°2 …n°3

DH … 0 …0…13A200
DL…1…10…403C0CC8
SH…13A200 …13A200…13A200
SL…403C0CC8…403B070B…403C0CAF
MY…10…0…10

The data from n° 2 to n° 1 go through alright even if n° 3 is emitting, whereas the data from n°3 to n°1 is completely perturbed by the emission of n°2.
I suppose there are interferences somewhere, but I cannot figure out where?
Maybe my addressing is not correct?
Any help?
Thanks!

If node 2 is sending data to node 1, i think there is no need to send data from node 2 to node 3 and then the same data from node 3 to node 1.