There is a (new) display error with the internet explorer on the front page:
Settings in Home Page Design:
Portfolio items displayed: -1
Category: Featured
Reload the front page (a few times) untill the error appears.
If the Category is set to "…
Thanks a lot. But the CSS solution isn't really useful. If I assign two different categories to a single portfolio item and exclude one, it doesn't show up under "All".