[Wine] Application is listen to UDP port but no output

[drunkenchicken]

Hello Wine Forum,
I searched some time before i wrote this message, but maybe I just used the wrong keywords.
I'm running a test version of Win-Test (www.win-test.com) and I tried to run it in Network with an Windows Laptop. The network communication of this software is running over udp port 9871. If i send a request from the Laptop to the wine application i see the correct reaction on the wine screen, but i don't get a get a feedback on the windows machine.

I used Wireshark to debug the network traffic and i discoverd on eth0 only traffic from laptop to wine application.

I tried to open the ports with:

Code:
sudo iptables -A OUTPUT -p udp --dport 9871 -j ACCEPT


but the same old story.

Some ideas out there?

Thanks Olli