Spring RTS Engine

But on my other computer which also has an (albeit far superior) ATI runs it smoothly.

But how could that happen if everything else is fine, including other 3D games like AoE III (and a few others)?

Well, my computer always worked a charm with Spring, it would play your final frontier, yer XTA, yer BA, anything. But now all of a sudden it doesn't like it. I open it up, start a game and the screen splits into lots of bars and scrambles them up a bit. I would show you a screenshot of this phenome...