I recently started using the software and i've burned a few movies. They were saved as .iso and now for some reason when i backup a dvd to my hard drive it's saved as audio_ts and video_ts, which won't burn to a blank disc.

Helpppppp

AUDIO_TS and VIDEO_TS are folders. These folders are on your originals. VIDEO_TS contains the video files. Why won't they burn to disc? What steps are you taking?

Well i'm put the source as the dvd and the target as my documents\dvdfab\ just as it was originally. At first the saved under the "ISO" folder and i could click on that and then it would have the icon for the movie, which is .iso format. Now if i choose the full disc it will make a "full disc" folder and main movie makes a "main movie" foler, which has the video and audio ts.

For some reason it's not saving under the ISO folder, which was working fine.

please read the official guide and come back with further questions.
http://dvdfab.com/docs/

to burn video_ts folder click the folder for source, navigate to the video_ts folder and click okay.