If Minthara is an active party member during ACT II's finale; Jaheira will completely cut out the dialogue audio of an ongoing scene whenever she initiates her idle conversation with Minthara in the background.
*As can be seen whenever Minthara and Jaheira start conversing in the background during an ongoing scene, the scene will entirely cut dialogue audio. Which kept happening so frequently it required full investigation as to what's causing this since Art Cullagh, Withers and Cerys lengthy scenes were impossible to properly experience*