DVD2ONE Not Enough Space On Disk?

Hi, I just d/loaded and registered DVD2ONE and did a full movie of Back To The Future (pal) When I try to burn using Nero it says not enough space on the disk, so I deleted a single IFO and a couple of VOBS containing Macrovision protected bla bla bla at the end of the film (only about 10mb) and that worked fine?
Is this a common thing to happen when using the program DVD2ONE? Does it make the movie ‘slightly’ too big for the disk or not take in to account some extra video that appears at the end of some movies?

Reduce the output size in DVD2one to 4444mb and the problem will go away.