"I have a macbook 2.0 c2d running windows XP Pro in bootcamp. It [Titan Quest] will NOT play. The game is installed and patched.

Error message is Fatal Error Couldn't initialize graphics engine."

As I understand the situation, Mac software and hardware are designed to work with each other; the same applies to Windows software and hardware. Some people have loaded Windows onto a Mac with no problems: they lose some power, but as long as they are only using word processing programs, etc., they are usually okay.

When you start adding Windows games, these games not only aren't designed for Mac hardware, but they often cause problems on Windows machines. Two posters on the Mac thread said that they are running Windows games on Macs with no problems, but they were referring to older games.

Titan's Quest is so advanced that a lot of Windows machines have problems with it. Loading it onto a Mac is likely to make things worse.

Future, more powerful Macs might be able to handle it. But I wouldn't expect it for a while.