So, using Ikaruga CHD from MAME 0.165, I've put it in the roms directory alongside the BIOS roms.
When I run it: File -> Run Naomi/Naomi2, and then double click it from the list, Demul crashes.
I have tested it with some other games, also. The same thing.
Other ROMs from MAME 0.165 [not CHD] run fine.
I'm running Windows 10 - 64 bits.