I play the resulting .iso file using VSO Player
I'm all for using software players as one step in testing, in order to avoid burning disks. But I have found problems in every software player I've used except Total Media Theater 5 (too soon to tell about TMT6). Generally, most do basic play okay, but subtle menu issues, and especially slideshow emulation, often is a problem. Layer breaks seem to me to be one area that is likely to reveal problems in the software player, even if a burned disk would be fine.
If have not tested VSO Player. If you burn a disk (I would), let us know if it shows that VSO got it right (or not).