Whatever it may be it is highly unlikely that the IP address changing is causing these issues.
If it were none of our customers could ever used DHCP. The "reporting Server" line in the XML file is left over from previous versions of Vipre and is no longer used in the current version.
All communication between the VIPRE server and Agent is done via the agent portion of the software. The policies are set to contact the server on a dns name.We have installed the Vipre console, which is providing updates to clients.The problem we run into is that clients that are listed in the console are being contacted at their initial ip address.This status is set when the agent has missed more than 3 checkins with the VIPRE server.That could be anything from a network issue to the agent software hung on the machine and stopped sending in the hello calls.192.168.0.18 is an old IP address (are some clients still reporting to that old server, which is down? On the Vipre admin console at the Communication part it only has the Vipre DNS name. Based on the information you posted at AM today the updates are failing for another reason.