This may be by design but it is changed behaviour from Beta 4 to Beta 5 so I'll report it anyway, just in case.
Thanks for reporting it. As stated in your other report, I really dislike all of these underlines on hover. I'd rather they changed color, than underline.
Beta 4 was a regression in this case, I believe. So this one is as expected. ("Concealed" links should be hidden until hover.)
Code: /* Remove the underline from the copyright text */ #copyright .concealed:hover { text-decoration: none !important; }
You might be interested in this thread then: http://xenforo.com/community/threads/remove-the-underline-on-hover-from-the-footer-links.8974/