Thanks Lordmonkus.
I tried to downlaod pleasuredome romset, but it is more than 70 GB... To get CPS-3 roms it is excesive for me.
I downloaded again those roms and their bios from several websites, but none of them seem to work with MAME. It is quite amazing, as Nebula works with CPS-3 many years ago, and it seems that MAME is not able to make it work as easily.
I would prefer to run all my arcade games througn MAME using Launhbox, but I think the easiest solution is keep using Nebula, even when it can not be launched with Launchbox.
Thanks for your patience.
Best regards.