WEB server: apache 2.0.58
O/S: gentoo Linux distribution
browser: Firefox 18.104.22.168
This problem is quite annoying but I have not seen it reported anywhere.
When a document contains shaded blocks formatted either by indenting the text, <code> tags or <file> tags the shaded blocks obscure the automatically generated table of content if the blocks are close enough to the start of the document.
I believe it should be the other way around - i.e., the table of content should obscure the blocks because you can always ``roll up'' the table of content menu if you need to read the text in the shaded blocks.
This problem can be seen, for example, in the dokuwiki syntax document that is included with dokuwiki installation but I'm also including a sample document file that shows the same problem when viewed in dokuwiki.