WOTLK updating itself to cataclysm

Hello, so i invited a couple of my friends to play on warmane, after downloading they all told me that after they log in, it immediately starts updating to cataclysm, i've tried google,forums.. and yet i found nothing.. i would really appreciate if someone could help me ;_;

they have to log-in by using their Warmane AccountName, not forum nickname or Email address.
If their clients are not 3.3.5 anymore because of the update then they have to download it again