Another one: If you have Edwin with you, and also acquired the quest "Prisoner of the Gnolls" (journal entry 27171), when you find Dynaheir you can either recruit her into the party or kill her. It looks like if you recruit her, the script erases 27171 along with several other related Journal entries regarding rescuing/killing Dynaheir. But if you kill her, it does not erase that particular entry.
Not sure if this is a BG1NPC related bug, or a known one that's been kicking around for a while.