DVD Talk Forum - Technical question about time skipping

This is a strange one about standard DVD/vob format. I have an old burned DVD (ripped from a laser disk,at some point, I believe) and I have managed to rip it to vob files in a folder on a hard drive. I can play the DVD using VLC. The progress bar displays correctly and the total and elapsed time both display. But when I attempt to jump forward by clicking on the progress bar, it will not jump past ~25 minutes. This seems to be the start of VTS_02_2.VOB. I have tried playing each vob individually and they play fine and are able to jump forward and backwards inside of each of their timespans. It is only when playing the entire folder as a DVD that jumping with the bar stops working. I went back and tried it from the optical disk, and it had the same issue, so it's some problem with the original formatting of the files.

I'm assuming it has something to do with the .bup files, but I don't know how to read those. Does anyone know what could be causing this and how I might attempt a manual repair?