[quote=BriMonster;2046648]…the original disc I created played just fine on every player I tried, the new one did not…[/quote]But this could be explained by a different disc being used for the copy. You should certainly investigate this first before going for a complex reauthoring scenario.
[quote=BriMonster;2046648]Also, I burned several copies, very slowly, just to be sure with the same result.[/quote]What is “very slowly”? Contrary to your expectations, burning well below the recommended speed rating of the DVD disc is [B][I]less[/I][/B] likely to make it compatible. Can you please just give us the brand and if possible the media ID of the discs you’re using? Use CD-DVD Speed to get this (under its Disc Info tab).
[quote=BriMonster;2046648]Upshot is, I’m thinking your IFOEdit idea is the way to go. The DVD has an intro show, one menu screen and four shows.[/quote]Ah well… IFOedit can’t easily deal with menus and multiple video title sets (VTSs); it is just a basic reauthoring tool for single VTSs.
I would suggest you use DVD Shrink to simply do a basic reauthor: i.e. not applying any compression but keeping all the menus and VTSs. Copy the VIDEO_TS and AUDIO_TS folders from the DVD to a separate folder on your hard disk. Then open with DVD Shrink, answer the various questions about where to put the results, and away you go.