I've got graphical issues with Grim Fandango on mine, which are annoying and block a lot of the view during gameplay, but conversations and cutscenes remain intact. Very stylish game with some hilarious puzzles (trying to get strip-searched to borrow a metal detector, distributing communist literature to union workers to insight rebellion and get their tools, trying to find a gun to gain the trust of someone (Meche) who thinks you're hiding one, etc…). Oh, man, I ned to play it again when summer starts, haha.
For your speed problem, I don't know if it will work, but try this.
And whatever did become of Largo? He went from supposed main antagonist to relatively minor character within one third of a game, haha.