Greg,
can you please email your piwik URL, login, password, and if possible your FTP login and password to hello@piwik.org ? we haven’t been able to reproduce this error and already two users reported it. we would need access to the server to debug.
When I try to add a user the page ask me for “Connect” and “Alias” - when I submit with green tick this message is thrown in a red box:
The parameters are not valid. The method called requires 3 parameters. Please check your URL and the method API.