Recently I had to undertake an IP change on a UAG array, after having made the IP change on the interfaces on both servers in my array I needed to update the portal configuration within UAG to bind it to the new IP address, annoyingly only one of the two nodes was showing the correct address. I tried various things including removing & re-adding the troublesome node to the array. Eventually after some research I found some information which pointed me towards the uag.map file in the C:program filesMicrosoft Forefront Unified Access Gatewaycommonconf directory. This file has some (not all) of the UAG configuration stored within, including IP addresses bound to the nodes in the array, I updated every incorrect entry to the correct entry, saved the file & reloaded the configuration in UAG, finally the correct addresses were being reported.
This is obviously not a supported / documented / recommended thing to do! (be very careful & take a copy of the file before you change it) In my situation I was rapidly coming to the conclusion re-building the array from scratch was going to be required, so I had an ever decreasing amount to loose by making the edit.