This error is typically related to Windows clients trying to dynamically register themselves with DNS. Since OpSource currently does not support DDNS from any sources, you should manually disable the clients option to try and register itself.  You can do this by going into the properties of each network interface that is configured with an IP Address and perform the following:

1. Select the TCP/IP properties for the adapter and click on Properties
2. Click on Advanced
3. Click on the DNS tab
4. Uncheck the Register this connection's addresses in DNS check box
5. Click OK and OK and Close
6. Repeat this for each interface that has an IP Address assigned to it