Hi, I have Orange Box and Day of Defeat for Steam which worked fine. But after receiving back my imac from applecare and reinstalling Snow Leopard it won't allow me to play online. On DoD and TF2 it loads up to the menu screen but when trying to start a game it has the message, "cd key authentication invalid for internet servers". It's as though i'm not logged in as it says on the screen "Welcome Back, Unknown". Half Life 2 works fine. My method of backup was to copy the steam folder to external drive and then back to ~/Library/Application Support/ Am i missing something simple here?