That is the same problem I ran into.
I have the Sync on Green setup and everything works great on my monitor exept 2 things. The first Matrix game, and Gentoox (my preferred xbox linux distro).
I tried a few different bios/mode combinations and still couldn't get linux or the game to work. Pitty being that Gentoox it is a computer operating system, and Enter the Matrix claims to be 1080i, yet I am forced to view them on a crappy TV.
I gave up too until I either a buy a frozen cable(not likily unless amazon decides to stock them) or buy a LM1881n(even less likily).
Good luck stevewal.
This post has been edited by xboxmods2977: Feb 25 2009, 10:46 PM