Hmmm, I think I did what you said, but it didn't seem to work...
Here's what I have now:
As you can see, I have PCG 1 open and have "Next PGC" set to #2. When I export the DVD (both test and full export) hitting the next button makes the movie jump to Title 2 - Chapter 1.
I also have "Next PGC" set to 3 for PGC 2 (which has 6 programs). When I hit next on the 1st, 2nd, 3rd, 4th, or 5th program it works as expected, but when I hit next on the 6th program it doesn't do anything, the movie just continues playing.
Keep in mind that playing the dvd works as it should.