TyTool can attach a VOB to other VOB to create a continous playing movie DVD.
So you have bad1.ty and bad2.ty (bad1 with some bad part first and bad2 after that). Take bad2.ty and create a VOB with the good part, then bad1.ty and start the cut after the bad part (is it better if the program has commercials and you want to cut them, is harder for movie only but it can be done with FAE). Create VOB and you end with bad2.vob (that is the first part) and bad1.vob (that's the second part). Enter the create IFO files/folders, select bad2.vob as only vob, then in the menus select attach bad1.vob, and the final dvd will play both parts as it was only 1 program/movie.