Having trouble burning DVD+R DL. When I try to burn a DL DVD I backed up, it appears that its burning but when i try to play the DVD, it doesnt work, the computer doesnt acknowledge it and my 360 freezes up. does anyone know how to fix this??

With the little amount of info you gave all I can say is lower your burn speed. What version of dvdfab are you using? What are your settings for dvdfab? What brand is the dvd+r DL blanks

I am using DVDFab 5 and burning with 8x DVD+R DL GQ Brand disks.

That's your problem bad blank media! Try burning at 4x and also check the set booktype to dvdrom. Get some better media. Verbatims DL is what most recomend and SL get verbatim or taiyo yuden. There is a new released version of dvdfab. it version 5.0.5.0 EDIT: What are you trying to do full disc main movie customize or a mobile option. Need to know in order to help you

Im burning full disks from backup file

The only reliable DL discs are Verbatim 2.4X Made in Singapore.