My computer is as follows:

AMD Athlon 64 4000
2 gigs of PNY Ultima RAM
NVidia (PNY) 6800 GS
ECS KVN1 (Light) Motherboard

I've had 2-3 CTDS (by the way, what does this stand for?) while playing. It was happening when I hit end turn. I tried making different decisions in terms of building structures and moving units, but nothing helped. I rebooted my computer and then hit end turn without enabling the script or issuing any orders. This solved the problem.

My OS image is 2+ years old, and I've installed various Rome mods over the past two years. My OS is stable, but I could use a re-image, but I just hate doing it.