I was setting up another user to use our SVN repository. He didn\'t have a username/password, so I logged in with my credentials. We now have a username/password for him.
After struggling with this and trying all the answers on this page, I finally realized I had the incorrect credentials stored by windows for the server that hosts our subversion. I cleared this stored value from windows credentials and all is well.
http://windows.microsoft.com/en-us/windows7/remove-stored-passwords-certificates-and-other-credentials