A bug ive seen for a few betas, but hadnt worked out fully because they have been coming so fast!
I don't know if this bug is because I start on a map at the cloth level or not, it should be easy to replicate, just start 5-10 games and look for the 4 blank squares around mountains and hills.
It seems that the main mountains on the cloth map don't show properly, but the issue gose away on a loading of a saved game.
Saved files seem to be both a blessing and a curse, they fix some issues and cause others.
http://ewom.sjwt.org/2010-12-13/
