Update to Rails 2.3.1. (Actually, not quite. Doesn't look like 2.3.1 will be released today, but I REALLY want to push these bugfixes out.) Removed bundled Rack (Rails 2.3.1 comes bundled with Rack 1.0). Add config.action_view.cache_template_loading = true to production environment. Fix FastCGI bug (http://rubyforge.org/tracker/index.php?func=detail&aid=24191&group_id=186&atid=783). Fix WikiWords bug (http://rubyforge.org/pipermail/instiki-users/2009-February/001181.html).
Updated to Rails 2.2.2. Added a couple more Ruby 1.9 fixes, but that's pretty much at a standstill, until one gets Maruku and HTML5lib working right under Ruby 1.9.
As a side benefit, fix an (non-user-visible) bug in display_s5(). Also fixed a bug where removing orphaned pages did not expire cached summary pages.