the regex url mapping has one problem

hello
 here is my url mapping code
 urls = (
    '/', pre_fix + 'public.Index',
    '/login', pre_fix + 'public.Login',
    '/register', pre_fix + 'public.Register',
    '/verify', pre_fix + 'public.Verify',
    '/validate_email', pre_fix + 'public.ValidateEmail',
    '/validate_username', pre_fix +
'public.ValidateUserName',
    '/shortpost', pre_fix + 'weibo.ShortPost',
    '/(.*)', pre_fix + 'weibo.UserIndex',
)
the last url is for user name mapping.
when i input url such as http://host:port/login, the login module is
executed and render correct html into web browser, but i find the last
url '/(.*)' is also executed. it is not correct,because i just want to
the last url mapping to map user's name.
 above code like the official code example(wiki), here is the the url
mapping of wiki:
 urls = (
    '/', 'Index',
    '/new', 'New',
    '/edit/(\d+)', 'Edit',
    '/delete/(\d+)', 'Delete',
    '/(.*)', 'Page',
)
could you please see my problem? thanks a lot