"Allow multiple registrations from the same email address?" is not respected

"Allow multiple registrations from the same email address?" is not respected when the additional participants use the same email address as that of the primary participant. This results in overwriting of the primary participant w/ the information of the additional participant (and no contact created for the additional participant) as described here :

http://forum.civicrm.org/index.php/topic,11568.msg49685.html#msg49685