So, about two and a half years after I broke the random short-answer matching question type in the Moodle 2.1 release, Jean-Michel Vedrine has finally fixed it. The fix will be in 2.5.5 and 2.6.2, or this week's weekly releases. The tracker issue is MDL-27414.
I just wanted to say thank you to Jean-Michel, and to the other people who helped work on it.