Hello Wanmil, Here are the facts : I downloaded the latest Ireland.osm from geofabrik (yesterday was 2010/02/05) and the latest one from Cloudmade.com (2010/01/26). Ireland coastlines data are complete. I tried with same options all versions from 1560 to 1494 and splitter version 105 only. Ireland map is in one area. I made my tests with multipolygon with close-gap option set to 1000 and 10000, and also the no-mp option with funny result : Ireland became a sea. As I thought it could be a problem with my style files, I made also all my tests with default styles provided with mkgmap and the results were the same : after version 1512, mkgmap is not able to produce multipolygon sea, despite "generate-sea=multipolygon,close-gap.=1000" works fine with v1512 for Ireland. I know how hard it is to develop a software such mkgmap (which is really good), but the problem may be not the data. Here is another vicous bug : when "merge-lines" is used, when you try to define a waypoint in route edition mode on a road in Mapsource, it is located far from your choice. You can also watch the problem with automatic popup which are not displayed under the mouse pointer, but elsewhere, sometimes out of the visible map area. Cheers, David