Yes, I did. But it only writes data files, and from the docs it seems that audio files require special handling.
Anyway, I got my code working. It was simpler than I thought - I was passing an empty ISOTrack and CDStamp object, when I should have been passing "nothing".
I thought I was going to have to deal with the event handlers to "feed" audio data to Nero as it is writing, but when I created the audio tracks all I have to do is set their type to "MP3" and it reads them and handles them automatically.
Now I'm having a small problem updating the status box from the logline event. It's a thread issue, but I'm guessing this has something to do with the way Visual Basic .NET 2005 is interacting with the COM library. I try to update the text of my status box in the logline event, and I get an error that it can't be accessed because the function is not in the thread the object was created in. Hmmm...