Welcome to CD Freaks.
This is a reasonably specialised question & as your thread title gives no clue about the question then you'll get many views as members have no idea what your asking about.
I'd suggest that you try out this type of project on to single layer discs first as dual layer burning can be difficult. Get some practice first.
Also what DL media are you using? If it's not Verbatim you're probably wasting your time with them anyway.