Your first action should be to update the video card drivers. If that does not work, check item #9 here: http://forum.paradoxplaza.com/forum/showthread.php?708168-Known-Issues-and-Solutions-to-them.
Edit: About what I said above. Not running a mod should be the very first thing to do if you have issues with the game. We can only help you with vanilla version issues.
More google-fu suggests that the Death and Taxes mod caused similar problems for some of it's users, and that the problem was resolved for them by downloading a smaller colormap.
http://forum.paradoxplaza.com/forum/showthread.php?621630-Frequently-Asked-Questions
Specifically, issue number 5.
I'm guessing their linked file will do no good, as it's for a modded map.
Edit: About what I said above. Not running a mod should be the very first thing to do if you have issues with the game. We can only help you with vanilla version issues.