My Sim City 4 crashes to desktop every 5 minutes

[yorkb13]

After hours and hours of building my city, the game crashes back to the desktop every 5 minutes or so.  There is no error message, no warning it just closes the game.

I have plenty of ram, a brand new HD video card that has updated drivers.  I have installed every patch I could find on the net for SC4. 

I have tried uninstalling and reinstalling the game 100 times.  It happens only when the game is moving.  If it paused for an hour while I build something it never happens.

I am at an utter loss on how to stop the crashing.

I have even tried what a lot of you suggested and turned off one of the processors while I run the game.  Still crashes. 

I am using Windows XP Service Pack 3

Please help me!