(This is a very simple 'drag with right click, select 7zip> unzip to \.*') Unzip EVERY game of the Romset, each to one folder. Looking for a way to do this in a full batch this can it be a problem.
I unzipped the rom, added just the ddsom.key, re-zipped the rom and bingo! it was working. Tested one game, Dungeons and Dragons - Shadow over Mystara. I'm still to find a comprehensive way to upgrade all the games of the Romset. Got the MAME Romset upgrade 0.177 -> 0.178. Since that's just me on this topic, let me at least register my findings so the next can make use of.
