They've stopped the invites. In fact, they essentially revoked invitations ... i.e. people I invited last night couldn't use their invitation email this morning

They've stopped the invites. In fact, they essentially revoked invitations ... i.e. people I invited last night couldn't use their invitation email this morning. Is that true? I was under the impression that the invites were not guaranteed and there was some sort of rate limit on the number of invites that were allowed to create Google+ accounts. I think your invitees can retry after sometime.