If you use DVDlab with tytool please help me find if this problem is present with you too.
- process your ty with TyTool and cut commercials
- import your mpeg into DVDlab 1.3b1 (mux/demux works the same)
- create chapters/ create index/ compile with force-index
- check the resulting VTS_01_0.IFO file with IFOedit to check if the chapters show the same frame number as the green diamonds (chapters) in DVDlab
For me it doesn't work. If this worked then is no need to use the GOP time code fix with mpeg2vcr.
If your souce is a movie and you only cut start/end (not inbetween) then you have no problem with chapters, if you cut several places then you have GOP time code problems that DVDlab can't handle to place correct chapters.