I had a similar issue a while back – think it was when I was trying to scrape Vectrex games. It was showing up as an unknown system.
I do remember getting an answer from someone saying the scraper looks at an online resource with the list of known systems – not a local resource.
I just ended up doing a manual scrape 1 by 1 since there was only about 15 game or so.
Doing a forum search from scraper source might point you to the right post.