I recently decided to go back to Civ'ing, and pulled my CDs out of my drawers, reinstalled it, patched, it, grabbed, some No-CD stuff, and started up a game. All going fine. I get to the middle-ages period, 1200 or so, and I start to notice something odd.... I hit enter at the end of my turn.... and wait. And wait. And wait. There will often be about a minute to a minute and a half where the screen is locked up, and Windows says that Civ4 is "Not Responding." It gets longer if I'm contacted diplomatically -- the offer will come up on the screen, then about three minutes later, the answers, and buttons will appear. This happens between every turn, making the game fairly stop-and-go, and terribly annoying.
I'm running a 2.08 Warlords, 2.66 Pentium IV, Raedon 9700 with 7.1 drivers, 1 GB of RAM. DirectX 9.0c. Not a dream system, but it suffices. Any ideas of things to try?

I have noticed that too but not as bad as you describe. What I do when that happens is exit out of the game and restart it. Seems to work a lot better after that again.

My system isn't as good as yours so, maybe you are playing on big maps too which will have that affect.

Ah, right. I'm on a... large map, I believe, one step up from normal. I thought it might be background processes or something, so I closed out my music, everything, even restarted the computer and it still did it. :S