I have been puzzled for a while by this: http://opengeofiction.net/#map=18/-45.70595/70.17565
There is a white 'island' here, but in JOSM there are no nodes or coastline ways there. It is over a month since I changed it. Originally it was a district maritime boundary which I managed to accidentally tag as natural=coastline. But although I've removed the coastline tag - and shifted the way slightly - the white area remains. So it looks to me as if the render hasn't updated on this bit of coastline. Can anyone tell me why, and if there is a way to fix it?