I can play the mods supplies with Civ4, Warlords, and BtS, and I can play SOME mods that I got from the Downloads section of this site, and I can play my own personal mod. I've tried putting FfH2 in the Mods folder located in Documents, and I tried putting it in the two mod folders that are in the Steam download area (When you go to BtS there a folder called Beyond the Sword that has a mod folder in it as well, which is the only one that works) Concerning the error messages, it just says BtS has shut down. I installed Steam in the default area. I installed Steam in all three of the folders i mentioned, none of them worked. I dont know what UAC is. Btw everything i just said is concerning my Mac, i dont use the Vista computer that much (Its the families computer, not mine) Sorry for not putting enough info.