When you do an operation on the map, I think Mappoint recalculte all data present in the current view on the map. More data you visualize, more time Mappoint will take to make changes to the map.

Try to do a goto to 0;0 location, with a zoom level that permits to visualize only water ('cause in the ocean there are no feature), then do your changes to the map (add shapes, for example) and then return to the original location.