I had a computer with a problem that aparently no one knows the answer to an eventually we found a solution. If importing .vob files into Adobe Premiere the video plays no problem but the audio cuts out after 30 seconds.
Converting the file to an .avi file works, but there another solution without having to convert the file. Go to www.ac3filter.net and download AC3Filter. Reboot the computer and try importing your file again after first ensuring it’s deleted from your catalogue in Premiere. Enjoy!