Static page problem

When going to tweedehandscaravans.org all kind of old pages show up.

please try the tab ‘Privacy’ ‘Fotos’ or ‘Werkwijze’and everything is as it should be. Click the home page ( the static page) and old pages appear. Also ‘werkwijze’ then gives a 404 because I recreated and renamed the whole page.
I also recreated the static page.

When declaring another page as static page the problems appear on the newly declared static page.

Problems stay when I turn off all the plugins.

Problem stays when I use theme 2010 – at first it seems ok, but when I click the static page I get the theme 2013 back again ( So strange, I almost do not dare to write it down..)

Any suggestions are welcome ??