Setting Up Dynamic ClusterCATS Fail-over or Moving from Static to Dynamic Fail-over Running CF 4.5.X on NT4.0/IIS4.0
When clustered with CF 4.5.x using static IP addresses, ClusterCATS IP Failover causes an Address conflict when the failed server recovers until it reboots and clears the IP conflict. This URL goes into considerable detail about how and why the problem occurs and how to detect and prevent it.
This article starts out exactly as the one above but changes in the middle. These are two different articles (believe it or not).
Setting Up Dynamic ClusterCATS Fail-over or Moving from Static to Dynamic Fail-over Running CF 4.5.X on NT4.0/IIS4.0