I'm seeing this thread when I'm very busy.. I had a similar problem. if you notice, you also can't share the documents that you are able to open via filebox.
I did not have to run terminal to solve it. I just noticed that there were differences when i plugged into my PC and chose mass storage or pc synch. using Mass storage, folders like DCIM and Documents were hidden.
To solve the problem, I copied the contents onto my PC and deleted the folders. Merely changing the properties did not help. Then create the new folders and paste everything back. Sorry for the long story