How to allow Windows 7 accept UDP messages from an external device with address "127.0.0.2"?

My firm produces some devices with a network interface. The devices are sent with a IP address = 0.0.0.0. The customers plugs the device on the private net in the field and, by using a tiny app written with VB6, discover it and set the correct IP address. This working by using UDP messages: the app broadcast a "Who's there?" UDP message, read back the answer(s) containing the MAC address of the device(s), and the the user send another UDP message containing the new IP address for target MAC.

Now, for some unknown reasons, one of these device get its IP address set to 127.0.0.2. The problem is that now the VB app can't find (via UDP) the device anymore, making it impossible to change the IP address to a valid one.

Further analisys revealed than if the app is running on Windows XP it sees the device, but if the app is running on Windows 7 the UDP message does'nt arrive to to the "socket" (while Wireshark can see the answer from the device).

Now, there a solution to allow Win7 to let "pass" an UDP message sent from a 127.0.0.2 external address? If yes, we could avoid to ship around the world a replacement device with a correct IP address and all the trouble of phisically mounting it in the field.

Here's a Wireshark capture of the "question" and the "answer" not "detected" by the VB app: cap.pcapng