I cant manage to have the small map of the world updated when I change it.. it stays the same... I'm so pissed..,

ReWorded the title slightly ;)

Bug Description:
When a change is made in worldbuilder, the worldbuilder minimap does not repaint to show the changes.

Expected Behavior
When changing terrain using worldbuilder, the worldbuilder minimap should repaint to reflect the changes.

Actual Behavior
When changing terrain using worldbuilder, the worldbuilder minimap does not change.

Steps to reproduce

Start a new game, and enter worldbuilder.
modify the terrain.
Observe that the minimap does not change to reflect it.