I have tried playing Doom 3 on my new machine running Windows Vista. Everything runs fine, except when I hit TAB to use the PDA, it is perpetually stuck on the blurb about how critical the PDA is and how to use it. It says to click to continue, but this does not work. I can hit TAB again to put away the PDA, but that's it. What is going on? How can I fix this? Any help is appreciated.