I don't know what the expected behavior is supposed to be, but it looks like there is a conflict between 'general' pages, and subpages for 'icecat'.
For example, "Add_to_Search_Bar", there is both a page by that title, and also a subpage for IceCat/Add_to_Search_Bar. The former is redirecting to the latter, and the latter is redirecting in some way causing a loop.
Did someone establish mod-rewrite rule in Apache/.htaccess, or is this all in the wiki application?