Program freezes when burning

I just recently bought the Video Converter Ultimate. Now I've been trying 3 (!!!) hours four videos (betw. 2 u. 25 min. Duration), which I have previously converted into VOB format, burn to DVD-R. A preview of the menu is on the triangle still available. "DVD create (convert DVD menu ...) - 3%" but then appears at the bottom of the window next to the plus sign just yet and that's it - no further reaction of the program. Have performed with several DVDs several attempts. On the discs, it may not be. I am very disappointed!