Age of Mythology: Titans. Crashes frequently

I recently bought Age of Mythiology boxed set that included the Titans
expansion.
It installed OK and was playing fine.
Then, once I got my first Titan and had it attack, the screen was flashing
shades of brown with elongated triangle shapes.
Then it did it when I had a battle with a large number of troops in a village.
Now, when I am playing, the games crashes to desktop after no consistant
play time.

I am running Windows XP SP3
Directx 9c
AMD Athalon XP 2800+
1gig of 2GHz memory
ATI Radeon 9600 series video card
driver 8.221.0.0
On board audio NVIDIA
driver 6.14.457.0