Just out of curiosity, I went back to the savegame that was giving me trouble, prior to my finding that I still had BI on my harddrive. That savegame functioned perfectly.

Since getting rid of the "secret" installation of BI, I haven't had a single problem with EB.

This might be important. I don't understand how, but at least on my computer, the presence of BI affected EB after one of the characters received a trait, that of "Auctoritas".

If anyone else is having trouble with this problem, or other problems for which an answer cannot be found, search you entire harddrive for the presence of BI, and delete it. Then, reload EB and see if it works as intended.