I don't know if these have been mentioned or not, but here are some bugs I encountered in single player.
1. Whenever I respawn as the wizard, i have to fire a spell once before I can change to another weapon.
2. Sometimes when I press the fortress key as the wizard the game crashes.
3. I don't know if this is a bug or not, but the highest level black magic spell tries killing you after you summon it.
4. Whenever I play a U4EF game, it seems to sometimes switch my player model to male commando.
5. U4EF makes my computer lag pretty badly. (especially when using wizard class)
6. When I don't run the .bat file the U4EF change profession window won't open.