I think I saw a bug today, but I haven't had time to reproduce it.

I was moving a page from the DOCPRIV space to the DOC space (Release notes for b4) and the page being moved contained a link to another page in the DOCPRIV space. After moving, the link was broken (it was trying to point to DOC:Link not DOCPRIV:Link).

Maybe moving a page doesn't update the links internal to a page to point back to the old space?