If you visit a page that does not exist yet, the create link is always lower case. Since the name of the page becomes the title this is important.
eg, visit:
http://geekout.org.uk/posts/NewPage
Create link is:
http://geekout.org.uk/ikiwiki.cgi?page=posts%2Fnewpage&from=&do=create
Not:
http://geekout.org.uk/ikiwiki.cgi?page=posts%2FNewPage&from=&do=create
This is a bug in Ikiwiki, and there is some discussion of it at http://ikiwiki.info/bugs/Titles_are_lower-cased_when_creating_a_page/.
Update: And now fixed in ikiwiki, and deployed here.