The configuration tool manifest is not set to ask for admin privileges (for vista and windows 7), so it cannot change the registry (and thus the routing configuration).
Actually, it manages to run on a standard (non admin) account, and you can "change" the routings, but as soon as you get out of the routing configuration screen, it doesn't get saved (and shows no error). If you enter that configuration screen again, it shows the old unchanged one.
Workarounds: run the program in admin mode manually
Expected behaivour: auto-ask by the UAC to run the program in admin mode
How to do it: adding a line to the manifest of the config tool as explained for example on the site below
http://community.bartdesmet.net/blogs/bart/archive/2006/10/28/Windows-Vista-_2D00_-Demand-UAC-elevation-for-an-application-by-adding-a-manifest-using-mt.exe.aspx