I've had two things that seem like bugs.  

-Altar offered me 700 gilders to go to war with Resoln, but when I clicked on it, I was at war but didn't have 700 gilders.  I thought Altar was more, like, goody-goody and honest than that.  

-There was a city with a pack of heroes inside the city, and also a small blob of heroes in the city environs but not inside.  I had a crash <NOT AN INTENTIONAL RELOAD -- HONEST!!>  and refought the battles.  The first time I went for the city first, smashed the heroes and garrison, and the nation fell so i didn't fight the other stack.  On reload,  I thought, hey, that was experience on the hoof going begging, so i fought the stack first; and when I hit the city there was no garrison.  I think the game thought the first battle on city turf used up the garrison -- but there wasn't a garrison there.