I have had DVDFab since Oct 2008 and I could not be happier with it. Some things you must do first is, make sure you have the latest version of DVDFab (6.0 Now) your burners firmware is up to date, make sure you have enough space on your hard drive, (10 Gig should do it ).
Do not use Memorex discs !! About 1/3 of them are bad. I use Verbatim DVD + R for 4.7Gig and under files, DVD + R DL for larger than 4.7 Gig up to 8.5 Gig. Disc made in Singapore, Japan and India are good. Discs made in China and elsewhere are a crap shoot. Do not use DVD - R worthless format.
They have an outstanding email support Ada E-mail Address(es):
firstname.lastname@example.org. They will help you with eveything !!!
Good Luck !