Vista - Civilization 4 issues.

Hey I'm running vista home premium 32bit, A 1.7Ghz processor (AMD Sempron 2500+), 1.25 GB or RAM, and an ATI Radeon 9600 video card.

And my problem is that when i run civilization everything is fine, until i actually start playing - while in fullscreen i get a completely black screen that flashes the gameplay should i minimize or start the task manager. in windowed mode i get normal gameplay until i actually click a unit or the map. My task Manager says that while civ is running my computer is running at max capacity. Any help appriciated, thanks!

Have you check if your computer does support the mininum requirements for the game?
Also, being on vista you need double the ram you read on the requirements.
So if the game asks for (example) 1gb of ram, you actually need 2gb or atleast 1.5gb
Check the requirements and post back here
you could also try This one for the future