Cisco Phones and ITL Files

I've noticed that, even when I change a phone's settings to point at an alternate CUCM cluster/node, if the phone has loaded a trust list (ITL) file, the settings won't take affect until you go in and erase the ITL file. This makes sense: the phone has been instructed to trust a certain cluster, and pointing it at an alternate untrusted IP is a risk. The first time it happened to me, though, it wasn't clear that the ITL file was keeping the phone pointed at the original CUCM cluster.