Proxy in Linux

Now, after some test, I have decided to move my PC from my LAN to a public IP.

Draftsight is unable to use my proxy setup in my Ubuntu 10.04

I get a DNS search sniffing my eth0 port, not an HTTP request.

After moving my PC to a public IP I get registration window with email request, put it and send it to registration server.

After this I have moved my PC back to my private IP, I receive confirmation email, visit page for  complete product activation, receive a wellcome mail but...... at startup DraftSight show the usual  window with:

Activation server not available. Please check your internet connection.

 

What I have to do for getting this registration complete?

Regards

Franco Spinelli