Redmine

I am having wiki pages in a child tree like this:

• Item

• Sub item A
• Sub item B

• Sub sub item B1

• Sub sub sub item X
• Sub sub sub item Y
• Sub sub sub item Z

• Sub sub item B2

• Sub sub sub item Z

• Sub item C

• Sub sub item C1
• Sub sub item C2

• Sub item D

Now the problem is that by using the child pages macro like this does not give me the sub-sub-sub items..:

{{child_pages(Item)}}

The wierd thing is that the index page (sorted alphabetically) does show the sub-sub-sub pages.

The child_pages macro just shows all childs of Item(sub items) and their childs (sub-sub items).
Is there a configuration parameter that can be changed to change this behaviour? Or is it hardcoded and might I be able to change the code?
The use of sub-sub-sub pages might seem far fetched... But the wiki I'm working was growing so large that we had to split up using sub-sub-sub pages.
We're using the ubuntu/debian package redmine version (1.1.3.stable (MySQL))