Really? That's the cause? I looked at the code difference and I can't see anything in their that would cause I crash. But if that really did stop the crash, who am I to doubt?
It fixes the crash with the save file Technomancer posted, which is all I can say with absolute certainty. It seems extremely likely to me that it will fix it for everyone, for several reasons: The save file crashes very late in the turnover process, right when diplomacy should be starting (which is obviously where this code would be run). JDog refers to the code in question as a "hack" in his patch notes, and if someone like him calls it a hack you know it's suspect. Technomancer has Vassal States set to Off in the game options in this save, which could
easily be part of the problem. The code I reverted triggers a call to an extra function that is not normally called there, AI_acceptSurrender(), which means there are more places in the sequence for something to go wrong. And so on.
I am also very confident that doing what I did will not spawn any secondary problems (provided you don't turn his HumanAsVassal game option on). As I said I am not nearly as familiar with the AI sections of the SDK as I am with all the other parts of it (b/c I haven't had to be), so I can't tell just from briefly looking at it what exactly was going on... though I can make a few educated guesses. I'm pretty sure I could figure it out but I don't have time right now; I'm trying to finish coding my own DLL for my full mod so my friends and I can start playing again. Basically I found
what was causing the problem, not why it was causing it, which is all I was trying to do -- get it working.
Yea I know, just been a while since I saw someone else doing updates for better AI.
That's because it's been a while since anyone has needed to, with JDog working as diligently on it as he has. And I wouldn't consider this an "update" b/c I didn't add anything new to it.

But I didn't have any choice, we wanted the stuff in 0.83 and I couldn't wait any longer for JDog to get back.
I was hoping to avoid having to post a DLL btw, lol, but since kind words will get you everywhere with me:
http://homepage.mac.com/klwelch/Civ4/DLL.zip