So, for once, my procrastination has paid off! A while back i was complaining, in the most polite way of course, about the lack of development of matchbox. A few days ago Zacharias released Matchbox RC1. He completely re-wrote it from the ground up and has made it 100% compatible with the latest Codeigniter release.
I downloaded the release candidate from http://codeigniter.com/wiki/Matchbox/, dropped it into a new branch of some projects that use the old version, and was off and running.
Thanks again to Zacharias for all your hard work.