I've seen oddball stuff like this before, where even EvolutionX 3935 kept bouncing back to the Xbox logo, although EvolutionX 3752 was happy.
Reason: videomode was screwed (ConfigMagic reported it as "unknown".
Fix: Enigmah Videomode Switchdisc.
AFAIK XBMP was the culprit. Always seems to be the last thing run before the video settings go all-to-pot, resulting in reboot loops, audio-but-no-video, or both. In all cases a copy of the EVS sorts things out.