The wiki is case-sensitive when it come to the 'recent posts' list.

At least for me, if I click a link to America (note capital letter), it shows no images at the bottom. If I click a link to america (all lower-case), the images appear normally.

Is this a known issue?

http://trac.donmai.us/ticket/1079

If I want to make a link and capital letters are involved, I get around it this way:
[ [trigger_discipline|Trigger Discipline] ]

Without the spaces between brackets, it looks like this:
Trigger Discipline

That way, it points to the correct wiki entry, and won't need to be fixed whether the issue is resolved or not.