These games will not play on Xbox version 1.6 in HD mode.
Curse: The Eye of Isis - Freezes on load.
Headhunter - Redemption - Freezes on load.
Hello Kitty - Screen is undersized in places.
Jacked - Screen is undersized in places.
Max Payne - Screen is oversized.
Mission Impossible - Freezes on load.
Outlaw Golf - 9 More Holes of X-Mas - Freezes on load.
Pirates of the Carribean - Won't unscramble in HD even when launched from evox.
Secret Weapons Over Normandy - Freezes on load.
Spartan: Total Warrior - Freezes on load.
Tecmo Classic Arcade - Freezes on load.
These games will be scrambled if launched from XBMC4XBOX but will play fine if launched from evox:
Arctic Thunder
Battle Engine Aquila
Commandos 2
Dark Summit
Fable
Galleon
Gun Metal
Gun Valkyrie
Hunter The Reckoning: Redemption
Jet Set Radio Future
Men of Valor
Mission Impossible
MLB Slugfest 20-03
Night Caster
Over the Hedge
Panzer Dragoon Orta
Quantum Redshift
Serious Sam
The Sims 2
Tetris Worlds
Voodoo Vince
Wreckless: The Yakuza Missions
My quick fix for the 2nd category is to just throw evox in the game directory and edit the ini to put only the game in the selection menu. So when I launch the game from XBMC4XBOX it loads evox and one click from evox loads the game.
That said, I thought I would share this info with everyone and also maybe give something for the developer of XBMC4XBOX to possibly fix.

Again, this is only when playing in high definition with component cables. These games all work fine in standard definition.