I've been running into a crippling problem wherein the length of time between clicking 'next turn' and actually being able to play the next turn of the game stretches to unbearable length by the renaissance/industrial eras of the game.

Everything is fine in the earlier turns. Everything seems to be running and rendering crisply, but by turn two hundred, two hundred and fifty or so, the length of time between turns runs from between 80 to 120 seconds.

I'm running on windows 7 home premium (64-bit), have an Intel Core2 Quad CPU Q9300 @ 2.50GHz, 8gb of RAM, and an ATI Radeon HD 4600 series which I believe has had its latest drivers installed.

Any suggestions would be greatly appreciated. These turn lengths are agonizing and preventing me from playing the game now.