Multisite privacy - passphrase protection not working

Hello,

I can't get the passphrase protection to work.. Although I set this http://screencast.com/t/yJLAZ8Eb

When going to cameleor.cobea.be, visitor is asked for a login+pass (= normal secure logging) and not just the passphrase.

Can you help me ?

NB: I'm using WPengin for hosting

Thank you very much