I find that both interesting, and disturbing.
Do you have a PAL or NTSC Xbox?
We have the same Rom lineup for sure, came in .gi file format correct? And is a bitch to extract. Infact, no known program can do it, even people with a registered (cracks don't work) Isobuster say they have problems extracting .gi.
As for your claim of compatibility, my Xbox is NTSC.
Random of the top of my head, what games do not work/run well :
Battletoads Double Dragon - horrible music file
Contra Hard Corps - runs once in 20 tries, and only on starscream mode, and then glitches up
Streets of Rage 2 - doesn't run
Streets of Rage 3 - doesn't run
Golden Axe 2 - doesn't run
Batman & Robin - crap music, screen goes black on explosions
That list above is enough to scrap the emulator, and I sure hope there's a solution to make them work.
I've only tested about 100 or less, and maybe 10 roms work.
This works great :
Shining Force 1
Gain Ground
Golden Axe 3 (poor intro, looks like a crash, then works)
So what's going on? Nothing wrong with my Xbox, I run xsnes all fine.