I've started encountering an issue where after loading a saved game, the game lags horribly (takes a second or two to register mouse clicks and everything moves at 3-4 FPS). The lag occasionally disappears while I'm doing things (haven't noticed a pattern of what causes it to go away), and almost always goes away after I end my turn. However, the lag appears for that single turn every time I load my current game. I hadn't noticed it before, so maybe it's related to the game being far along? My computer shouldn't be the issue, since as soon as I end my turn the game goes back to smooth sailing.