Thanks, Phil, that's helpful. Also, when I went back into the project, I noticed that on the Create Disc page, "Widescreen 16:9" was selected under video format. Perhaps that clashed with the 4:3 project aspect ratio. (You'd think it would check that before allowing you to do that sort of thing.)
I guess I'll stick to DVDs until I get all my older videotape converted.
And I don't think your guess was too WA!
Jim
PowerDirector 365, AMD Ryzen 7 3700X 8-core processor 4.05 GHz, 32GB RAM, Windows 10 64-bit OS, NVIDIA GeForce GTX 1660 SUPER