All fixed! All four games are verified clean copies according to redump. I meant to say redump before instead of no-intro. Oddly, Pac-Man vs. is so small (and thus is mostly garbage) that it grows larger
when zipped, so I zipped it with no compression.
Yeah, the scrubbing does seem a bit flawed. I hate to bloat downloads with garbage data but there doesn't seem to be a perfect scrubbing tool. Ideally I'd like to switch to full copies verified by no-intro, then someday if someone makes a proper scrubber I could offer both versions. The majority of scrubbed games seem to work though, so do let me know when you find problems and I'll hunt down a no-intro verified copy.
I'll check out Need for Speed Underground. It should be around here somewhere.