Where it talk about romset? ok read about it, but i had just single rom downloaded, and all work except on.. btw problem gone, the rom work nice in neogeo emulator with mame078 core, the problem was rom start with red screen and green one a bit glichy, and take like 15 second more then other core, and i supposed not work... My curiosity persist on why all Metal Slug series ( run well with default core except MSlug3, it has something different? Btw thanks for help hope this post can be useful for someone else who got same issue