After have installed a Matrox Millennium II with a Digidesign I/O card, The Mac will not boot, Pro Tools freezes during launch, or Pro Tools quits and OS reports an error (Type 1, 2, 3, etc.).It might be caused by the presence of the Millennium II. Remove this card to verify the problem.If it is being used in a Mac with multiple PCI Bridges (e.g. 9600), you could try to install the card in the last PCI slot (in a different PCI bridge from the Digidesign Hardware).