(all this baffles me. as previously mentioned i can varify, that my copy (kirin-release, untrimmed) workes perfektly in my 3DSXL, but when i put the gateway in my other 3DS, all the games work short of Monster Hunter 4.
Monster Hunter 4 was always a special case compared to other roms. for one, it always takes extremely long to boot, compared to other roms. another point is, everytime i close monster hunter (at least on 2.01b) it throws me back to the normal firmware, not the gateway firmware and i have to do the whole "DS-profile-shabang" all over in order to play another rom. what my guess is, that there is a problem with the region lock and circumventing it. what i cant wrap my head around are two things.
why is this problem not present with another japanese game (in my case "kirby") and why the heck, does it work on one 3DS, but not the other???
Thanks again to all who are giving insight and testing for us unlucky ones! I really hope, this can be resolved)
WOOOHOOOOOO I ACTUALLY GOT MINE TO WORK.
After another hour of trying and failing i actually thought of the SD card inside the 3DS being faulty because of issues that arose due to installing and deleting EMUNAND once in its lifetime. so i downloaded a tool called "Panasonic SD Formatter" (please google it, because i dont know if i am allowed to link to it here, should be easy to find) and formatted it with this tool and set it to quick format and format size adjustment within its options. now it works like a charm. still needs some time to load, but thats normal i guess. hope this helps the others, too.