AH! That's possibly the problem.
Let me guess... You had them on your card previously, and then updated them using PNDStore, perhaps? PNDStore pulls from the repo, and the MAME versions uploaded there (and, for some reason, Dega, as well) do not show up properly.
I would suggest grabbing them from the app-store, but that seems to be gone at present. I don't have my Pandora to hand right now, but if you would like me to upload the copies from my own card, which I know to be fully working, I'm happy to do so later.