Hi,
I found some errors in the Landpolygons:
http://osm.org/go/e7gakMQ-
or
http://www.4umaps.eu/map.htm?zoom=11&lat=59.249&lon=-2.48595&layers=B
Cheers, Marcus
It looks like it has already been fixed. But it might be a while before the Mapnik coastline is updated.