Problem placing buildings

I've run into some trouble trying to place buildings. It seems that I'm not allowed to place buildings in certain areas, even very open areas that doesn't seem to have any obvious obstructions. I have enough resources and no other buildings in my queue.

You can't place it there because it's a patch of trees. If you could place buildings on tree stumps, people could quickly just build over all the tree areas... which would be a problem no? x)

BB_Azariel