DVD Shrink 3.2 is what i use,and it uses nero to burn, some sort of "plug in" or something
just select "open Disc" from the menu's at the top.
It will analys the disk then give you some options. 2-3 minutes
9/10 i just remove all un-neccessary languages and shrink the menus/extras and so forth via the "custom ratio" option turn all these right down and leave the movie set at automatic, if this still doesnt work, use 8.7gig disc's its that easy.
Dual layer im still trying to learn, dont get much time on puter these days.