This isn't, surprisingly, another double-encoding bug - it's a not-enough-encoding bug. The Data Explorer doesn't like the question Do I really need to encode '&' as ' &'?.
Question title screenshot:
Data Explorer results:
Additional testing has revealed that jQuery: how to add <li> in an existing <ul>? and How do I translate a ® into Silverlight Text Represenation have their titles encoded properly - so it's just
& that trips it up. What gives?