Ooh interesting! I think the easiest way for you to get to OF now is... to use a different display. I've just sold my 30" Cinema Display because it was too much trouble - it has very low tolerance to screen modes. For some reason OF must be trying to use a resolution your monitor cannot display. It could be the cable (too bad it's not removable from the display...). Try connecting it to the 2nd output if your card is a dual DVI one.

Anyway... once you do get to OF, type printenv and see what the boot variables are. I'll look into my OF vars later and paste what those should be...