Hi Nico,
Thanks for reminding me of the URL, I manually edited the header.php with the correct URL to the image. And the header does show correct now.
Of course this isn’t the way it should work, but it did.
I probably tampered too much with my installation.
I have tried to move my website out of the ‘WordPress’ folder but didn’t succeed. But in a few month I will have a new website anyways. This was just to have the new logo already in the old website.
Thanks and have a nice weekend.