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.
Updated Instiki to Rails 2.1 RC1 (aka 2.0.991).