Attached are two very simple osm files which show an "island" in a water polygon added by hand. Both are connected with a multipolygon relation. The difference between the to files is just the size of the island. The multipolygon is rendered correctly in the map resulting from test1.osm but not in the one resulting from test2.osm. This may be the result of a bug in the polygon splitting algorithm. This problem also occurs when I try to create a map of Corsica with the sea added by hand. Best wishes Christian