The problem is on disk 2, about a third of way through the 2nd episode (the episode called "HELP! Shabranigdo is Reborn", as they enter Rezo's tower, the disk is broken. I tried it on two players. On my Panasonic player it manifests as playing about ten seconds of video, then freezing for a few seconds, then skipping back about four seconds, then playing for ten seconds, then freezing, and so on. I also have a cheap and cheerful USB DVD player, and the video simply fails to play at the point that the problems start.
I was mighty happy when my latest copy played with no problems!
The timer on your media player will give a cumulative time for all the episodes on the disk, rather than a time per-episode. I think the problems happened at approx the 33 minute mark.