JS-R reported a bug in the JSRDocs db, which took some time to figure out. I updated the server code to the latest version of the source, and then fixed some JS warnings, none of which was causing the problem. Eventually it turned out that there was a character 0x10 in one of the text fields; it's not allowed in XML, so it was causing Firefox to gack on any search results containing that record.

Not sure how it got in there, and not sure either how to protect against it; perhaps I need to add another component to the data sanitization code.