When I try to access [http://superuser.com/users/flag-weight/dragonlord](http://superuser.com/users/flag-weight/dragonlord), an HTTP 500 Internal Server Error occurs.  However,  accessing [http://superuser.com/users/flag-weight/73918](http://superuser.com/users/flag-weight/73918) does not. 

Can this be handled more gracefully, such as attempting to looking up the correct user ID?