Ouch! There are several reasons. Here are a couple. Your DVD player probably won't recognize a CDR as a DVD under any circumstances. Most players do a media check first, see that the media is a CDR, and know that it can't possibly be a DVD. A DVD player needs a full and internally consistent title set (i.e. a collection of IFO and VOB files). In a way a title set constitutes a program, with instructions on what menus to display when, and what happens when a user clicks the menu buttons. The player simply cannot play a part of one VOB.