Here is what I got to work. Hope that it solves your problem.
Permalinks set to just Post name: /%postname%/
(Be sure to hit the Save Changes button)
Hello World post is http://charlett.no/hello-world/
Uncategorized category is http://charlett.no/category/uncategorized/
Thanks for your answer, but that doesn’t work. If I choose “Custom Structure” and write /%postname%/, then my category links doesn’t work.
It sounds like our confusion is around “my category links”. I’m not clear on what you are referring to.
In my suggested approach (above), to view all the post in a category, you code a URL that ends /category/apples if “apples” is your category.
If you hand-coded category links, you would have to change them. But all the automatic ones in WordPress work for me.
When I say category links I mean the links on the side of my blog that leads to different categories. I have for example own categories for fashion, psychology and everyday life.
In the method jonradio suggested, your category links should work. Can you change your permalinks to postname and let me have a look at your site?
Now my permalinks settings are like this: Post name: http://charlett.no/sample-post/.
You find my categories on the left side of my blog under “Kategorier” 🙂
My blog: http://charlett.no
