DVI-D does digital-only while DVI-I is both analog and digital. I have an ATI 9800 Pro which appears to be DVI-I and an LCD monitor which also accepts DVI-I.
Will a DVI-D cable work in this setup ? No analog signals would ever be displayed, but what would be a scenario where I need an analog signal to come through ? Or would I be safer with the DVI-I cable (but I'd rather force digital by using DVI-D... DVI-I auto-switches but I don't want analog at all if I can help it). Hope that makes sense.