Do you have the 204MB CHD?
A Compressed Hunks of Data (CHD) file is a hard drive, CD, or DVD image.
Scott
EDIT: Just noticed that it is flagged as non-working in 0.146 and doesn't appear to have been fixed yet.
From 0.146 MAME Info.dat naomi.c info
Bugs:
- All sets in naomi.c: Crash after OK. Tafoid (ID 04838)
WIP:
- 0.145u8: R. Belmont fixed some crashes in machine\naomigd.c and naomim1/2/4.c, there are more.