Weird problem burning dvds with nero

I just started backing up part of my DVD collection. I used Super DVD copy to split the data onto two disks and to copy it on my harddrive. I got the video_ts folder and all that stuff. Then I used nero and burnt each dvd. Now for the first two movies it worked great. Then when I tried the next one something weird happened. It seemed to work fine. It finished burning, and I even tried it on my XBox and another DVD player and it worked perfectly. The problem is, it won’t run on any computer I put it in. The computer can read the name of the disk, but won’t play on any software player, (I tried Power DVD, Windows Media Player, and VLC, an opensource dvd player). Thinking it was a fluke, I tried another movie, and same thing happened, can anyone help?