Blocky city borders - antialiasing issue?

[vg_ranger]

My city borders are big, colored blocks. The entire tile is colored that way, whereas in screenshots it appears that it should fade out. My guess is that this would be an antialiasing problem (?) but I've disabled it and it still didnt fix the issue.

Here's what it looks like:

http://img323.imageshack.us/my.php?image=civ4screenshot0000s8xb.jpg

I've got a Geforce7800 gt, athlon 3500+ cpu, 2gb of ram, winxp.

Most up-to-date directx, drivers, win updates, etc.

Any help?

[vg_ranger]

If its any help to anyone else - uninstalling the game and then reinstalling seems to have fixed it.