So, seeing this issue come up, I hesitantly installed the AC3 filters again, and all was smooth...but, of course, when I tried to fire up nvDVD, no dice. I even updated to the latest version...which proceeded to not work at all, claiming some incorrect parameters (which the program itself set up!). One might simply ask "Why not use another DVD player/program?" I really like nvDVD, primarily because it would do screen captures AND audio captures. I haven't found any DVD software yet that will do both of those operations AND is worth a shit. One or the other, sure, in fact, most will do screen captures, but audio capture seems to be the deal-breaker. But, in all honesty, nvDVD is legacy software, and no longer supported...
So, that was that. That was the last straw...away it went, and the search for new software began. I've tentatively settled on DVD X Player for now. It seems to be the one with the fullest functionality (but, notably, no audio capture), so I'll go with it for the nonce. If anyone has any software they'd like to suggest, I'll give it a try...though, if it doesn't have audio capture, then it's probably not any better (for my purposes) than what I now have.
Just time to let go, I guess. Hate to see it go, but gotta get with the times. I've noticed I do have a tendency to stick with a program, when it works well. Hell, it was only recently I updated to a new FTP program...the one I was using was YEARS old and out of date, but I was just used to it.
And all this came up because I was trying to create a VCD. Cripes...