Ok, I try to laugh about this but....
Well, let's start from the beginning:
I choose "Single Sign On"
I'm redirect to http://go.sap.com/index.html
Again, i click on the picture
I put my credentials (mail + password)
... and I'm identified like poor @mikael.lindskoug (maybe it's a trial account? I do not know... Former Member)
then I click on "account settings" and I'm redirected to my profile
Apart that SSO it's not working (I was logged on Open Sap ), apart that no message at all when SSO it's not working, just a redirect, apart having to put my credentials even if i flag "remember me", it's not so nice to take someone identity (I only hope Mikael is a Bilionaire and i'll be able to spend ALL his money).