You can click on the Google or Yahoo buttons to sign-in with these identity providers,
or you just type your identity uri and click on the little login button.
see (with ff): https://www.logilab.net/cwo/versioncontent/504366
seems already fixed, no pb with the provided link
Ticket #542285 - latest update on 2011/05/11, created on 2009/11/23 by Aurelien Campeas