I've been using MAMEoX with no problems for quite some time, at least nothing that isn't known. A friend of mine recently had me softmod his Xbox, and it's been working great, using the ultimate dash exploit, and NKpatcher to run unsigned code.
The only issue I've had is when I run MAMEoX, when I select a rom to run. Everything up to that point loads fine, but it waits at the spotted-loading screen for about a minute and a half. After that, it loads just fine, and plays great, until you decide to load a different title. It's mostly a pain in the arse, it doesn't seem to affect individual titles from working. Has anyone else had an issue like this?
I've tried reinstalling the emulator, deleting the save files, reducing the amount of ROMs in the list (tho that shouldn't make a difference, there were only like 10 in there...)