From 2007.igem.org

Q: My user account works on the iGEM2007 Registration page, but not on the Wiki. What is wrong?

A: If your user name has an unusual character in it (like at-sign or underscore) your account will work on the registration page, but may not work on the Wikis because the registration page accepts whatever string you enter, but the wikis process the userame string in various ways. For example, the wiki software converts underscore to space. The easy way to fix this is to send us an email with the old username and the new one. We can fix the database for you. - iGEM </div>