This might be more of a suggestion than a bug report, but meh.
When you talk to Burra he mentions that a pack of gnolls have kidnapped his daughter, but he also emphasizes that you'll get paid for killing the gnoll leader - not finding the girl. The journal, however, lists finding the daughter pretty much as top priority.
Either dialogue or journal entry should probably be modified, especially since the journal updates when you kill Ythorax, not when you find the duergar.