That is interesting. And all the more reason to exclude visited dungeons from possible selection
EDIT: Sorry Pango, to answer your question from five posts back, I'm still playing Daggerfall Classic, but I'm assuming that in keeping parity with the original game, DFUnity would not try and change the random selections. I have this feeling that the issue lies in the original game using a shitty seeding system, but trying to fix that seems a waste of time when compared with implementing a different system that ensures a fresh experience.