Ah, yes, very funny Sebastian. :-) I admit I laughed out loud at the comment, because it reminded me of how easy it is to ask the right question in the wrong way!
Let me clarify... When I select the "Edit" radio button in the top left, I am still unable to edit anything.
In fact, when the edit radio button is selected, all the content on the pages vanishes, and I'm left staring at empty containers. Very strange, I must say. I have never seen this behavior before in DNN.
I experience the effect when logged in either as HOST. I am able to add new modules to pages, but cannot edit those either.
When "View" is selected, I can see all content. When Edit is selected, content vanishes, and I cannot edit.
HOWEVER, When logged in as ADMIN, I am able to edit content now. The problem persists when logged in as Host.