New user cannot login with default password

When the new user creates a blog and received the activation email, he cannot login with the given password upon linking the link from the email.

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Howdy xxx,

Your new MU Websites site has been successfully set up at:
http://xxx.musite.com/

You can log in to the administrator account with the following information:
[Sensitive information is removed by moderator]
Log in here: http://xxx.musite.com/wp-login.php

We hope you enjoy your new site. Thanks!
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