SharePoint 2013 Authentication with Azure

Hi,

I have readthe followingarticle:  

http://social.technet.microsoft.com/wiki/contents/articles/22309.integrating-windows-live-id-google-and-facebook-accounts-with-sharepoint-2013-white-paper.aspx

I've set upaTrustedIdentity Provider. This workswell so farwith no problems.
Now I havethe problem, thatno new MySitesfordomain users are created any more. The process stops on thepage "We're almost ready!"
If Inow disable theTrustedIdentity Provider everything works as usual.
Why might that be? Have an idea?