ive had something similar happen to me, except when i hit the end turn button my game immediately CTD`s, which is very annoying, ive found with that though if i reload the game and look at my loadgame files the auto save last worked as it crashed so when i load the auto save up everything is fine. this too is totally random and has never caused me a major problem. if anyone else has experienced this and knows how to fix it plz let me know :)