I think the reason that no-one has come up with a definitive solution yet is that CTDs are happening at any time and for no discernable or repeatable reason. I had one CTD while I was away from the keyboard making a drink!
For me what has stabilised the game is:
1) Turn off Antivirus & Antispyware programs.
2) Run the game in a non-maximised window.
3) Drop graphics down to medium.
By doing these I am now able to finish games & have no CTDs. I have a Geforce FX5700 & latest drivers. However although many posters also seem to have NVidia cards my guess is that the key problem is that CIV4 is a monster system resource hog.
For me what has stabilised the game is:
1) Turn off Antivirus & Antispyware programs.
2) Run the game in a non-maximised window.
3) Drop graphics down to medium.
By doing these I am now able to finish games & have no CTDs. I have a Geforce FX5700 & latest drivers. However although many posters also seem to have NVidia cards my guess is that the key problem is that CIV4 is a monster system resource hog.

) I've played many games with Standard or smaller maps with only the "usual" problems of stuttering sound and the like, but now that I'm trying a Huge map game, I've had no less than 10 CTD's... And since one of the things I did to "enhance performance" was turn off the Autosave, well... "One step forward and two steps back" is fairly descriptive.

) , summarizes in Posts #122 & #123.
Its NOT what the issue is here.