Graphics Refresh Error in the Imperia Mod

[Graceheart the Leopard]

So I installed the Imperial Mod for Cossacks: Back to War on Steam on Windows 8, and I seem to have a very bad problem with graphics. The screen does not seem to refresh, so if I move my mouse around, I can't actually see where it is. If I manage to get into a mission, this is the only thing that I see:

I tried running it under XP compatibility (Service Pack 2) and it doesn't work. Can anyone else help me with this?