Samurai Persistence

After much trial and error, I figured out what the problem was. It turned out to be surprisingly simple... it seems that there are different versions of Heroes 3.1. I had the Gold version from Catalyst installed, and on that version, the campaign would freeze after capturing Yl'sire because the dialogue system that was supposed to play after capturing the castle wouldn't work. I downloaded and installed a different Gold version (I don't know who made the repack)... and the problem disappeared.