When a comment is added to page named "directory/page" it also appears in the page "directory".
This seems to happen at least with versions 3.20100815.6 and 3.20110225. Id didn't happen in version from about a year ago. I created a testing ikiwiki installation demonstrating this bug. The same comment can be seen at <http://rtime.felk.cvut.cz/~sojka/blog/posts/directory/post/> and at <http://rtime.felk.cvut.cz/~sojka/blog/posts/directory/>. The corresponding git repo can be cloned by