DocBook 1.78.1, file: common/titles.xsl, line 485ff:
[...] <xsl:template match="answer" mode="title.markup"> <!-- answers don't have titles --> <xsl:text>Answer</xsl:text> </xsl:template> <xsl:template match="qandaentry" mode="title.markup"> <!-- qandaentrys are represented by the first question in them --> <xsl:text>Question</xsl:text> </xsl:template> [...]
These seem to be missing gentext calls to make them localizable. On the ML, Bob Stayton agreed that this was a bug, although it would rarely crop up, since both elements usually only use labels, but not titles.
Mailing list thread: http://markmail.org/thread/bcsyc5ztg56fkbz4 .