the_maq,
I just played a game of super sidekicks 2 on ngcd without issue, it's possible your cd image is either defective or in an unsupported format. Make sure the cd images you get are in the trurip and/or bin/cue format. If you don't feel like procuring new images, there is a little easy to use/freeware tool that will convert to the proper format - check this message:
https://neo-source.com/index.php?topic=2487.msg26465#msg26465EDIT:Just realized that I broke fastforward w/neogeo under some circumstatances - it's fixed now, and I'm thinking this might be where the crash was coming from. Oops

It happened the other day while fixing another problem.
best regards,
- dink