I've just noticed that there isn't any support in the splitter for relations that contain other relations, even though it is permitted by OSM. This means that a relation won't be written to a tile if it contains other relations from that tile but no nodes or ways from that tile. I'm still a bit of an OSM newbie so aren't sure how often this is likely to occur or what the consequences are if these relations are lost. I'm not aware of anyone having mentioned it before now, so I guess it's not too serious a problem? Or is it something peopl have just been living with (possibly without even realising)? Anyway, I think I can add support for this without too much additional overhead (though recursive relations, and links through 3 or more levels of relations, makes things a bit trickier) so I'll add it to the todo list. Chris