We'd like you to uninstall IPAM beta 2 (or beta 1) and then install the RC.
There was an installer snag between beta 2 and RC that you should not experience, but we didn't set our QA staff on it to be absolutely certain.
If you do hit the snag, Microsoft's Installer technology may decide to not update any files and report it successful. Only a close examination of the logs would say otherwise.
Thanks Peter. We are cookin. Install went very clean.