Exchange socket

I’m developing an application on an RCM2100 which opens 3 TCP sockets.
A PC opens 2 sockets and send packets to rabbit.
Sometime it happens that rabbit reply on both sockets at packet sent on one socket only.
(Example: PC send a request to Rabbit on socket 1 and rabbit replies on socket 1 and 2).
I have done a lot of debug but I can’t discover where this problem comes from.
Someone has a solution?