IFOEDIT Losing Files

I have 13 vobs I want to use to create an image. When I use IFOEDIT to create the IFOs, it only does 11 of the files, then finishes, but with only the 11 files. I added the first 2 as #'s 14 and 15, so that I would fool it into continuing so it would process all 13. Then it finished after doing 12 of the files. I’ve tried changing the order, but same problem. The 13 vob’s are 4.14 GB, so I’m not over the limit.

What’s going on ?