Thanks Jeff.
I actually did test the DVD on a set-top player (mine) before getting it replicated. The DVD worked perfectly.
I was able to test my friend’s problematic DVD player yesterday. It apparently doesn’t work properly.
(I tested it with multiple commercial DVDs. It always ignores initial menus and goes straight to the first track it finds on the disc. It also automatically turns on the first subtitle track.)
Nevertheless, my DVD was faulty in that it didn’t ‘fail gracefully’ when the player wasn’t behaving correctly.
I’ll correct this in the next replication order. Meanwhile, I still have several hundred discs remaining from the first order, and I’m wondering how many other DVD players will act like this one did. Not many, I hope.