Expanding rooms and map effects

[Mentlegen]

So i expanded the parlor so that it would have two extra screens of vertical length. This screws up my map alignment, and when i try to fix it, every other adjacent room becomes offset too. How can i fix this?

[benox50]

Hold down M on the map editor instead of using the arrows, cause the arrows move the whole map (which is quite useful I must say)

Hold M and move mouse to move single room on map editor