When using EasyTutu or BGT, all NPCs will not voice their easter egg lines when you click on them a few too many times. This is caused either by those programs themselves or the BG2 Engine.
EDIT: This problem may be due to the BG2 Engine. If I am correct, NPCs do not have these extra lines and so they may be disabled when converting the original engine.
After a certain number of clicks on an NPC without giving them an order, they will voice certain easter egg lines (e.g. Minsc - "Fool me once, shame on you. Fool me twice, watch it! I'm HUGE!", Viconia - "I'll go where you wish, if you keep me from the accursed sun.")