The obvious things to try on Win7 are running it in compatibility mode and disabling visual themes. I never had any problems running it on Win7 x64, but I don't remember off the top of my head what I did (if anything) to make it work correctly.

Solved,
I changed it to run in 640x480 screen resolution, and it works fine now. Sorry for getting ahead of myself.

There should be other solutions that let you run it at a higher resolution. I've gone all the way up to 1920x1200 without an issue. At the very least, I think SMAC supported 800x600 out of the box.

I got a black circle around the pointer. Anyone knows why?