Coast detail?

I just dont understand this… The coast got higher detail at lower zoom level. Why?

Also the roads I edit show, but not the new coast I make? Im am doing something wrong here??

Samething here:

I think the problem is how coastlines are rendered on the mapnik layer, they use different sources for different zoom levels for performance reasons… I would recommend asking the same thing on the mailing list, something need to be done about this.

Yep, I also noticed this. It’s funny to zoom to a small island and see only plain water everywhere instead on all next zoom levels.