I found the answer... It did not work with firefox but with InternetExplorer :)
--
You received this message because you are subscribed to the Google Groups "Kobo Users" group.
To unsubscribe from this group and stop receiving emails from it, send an email to kobo-users+...@googlegroups.com.
To post to this group, send email to kobo-...@googlegroups.com.
Visit this group at http://groups.google.com/group/kobo-users.
For more options, visit https://groups.google.com/d/optout.