eZSubscriptionList::registerSubscription doesn't correctly check for logged in user.
I don't know why but the actual used function:

if ( $this->attribute( 'auto_confirm_registered' ) &&  eZUser::isUserLoggedIn( ) )

doesn't work, i had to change it to:

$currentUser = eZUser::currentUser();
        if ( $this->attribute( 'auto_confirm_registered' ) &&  $currentUser->isLoggedIn() )

patch attached against latest version

Steps to reproduce

part of other problems, see http://ez.no/community/contribs/applications/ez_newsletter#comments