Hi,
I have a sony projector as well. The DVI has to have both analogue and digital to pass directly to rgb. I have a momitsu dvd player which has both on their dvi output so I run directly to the projector with a dvi to rgbhv cable. It works great. Better than any component video so far. Make sure the 990 is both analogue and digital. I think DVI-d is strictly digital and DVI-I is both. Thanks