It's likely (very likely) a bad (mod) installation. If Macready was here, I think you'll probably be asked to replicate your problems on a clean install of Easytutu.
I can only give you my universal advice:
1) make sure you have a clean Easytutu installation handy, always. This is created by creating a "clean" backup(override directory, baldur.exe, chitin.key and dialog.tlk) - then, if you ever needed a clean EasyTutu install, you could delete your mod folders, override folder and weidu.log, and restore a clean backup. Saves time reinstalling.
2) Most causes of problems are bad installs of mods(any mods, really). Mods themselves are okay, it's just something went wrong during the install. So, when you install mods, do not install mods with the game running, do not run two mod installators at once, and certainly never install patches after mods.
That's it. If you follow these rules, restoring a clean backup(or, if you don't have one, then installing EasyTutu anew) and reinstalling BG1 NPC and starting a new game generally helps. Also, before installing any mods on EasyTutu, check that your game runs stable. It may crash from time to time, but by stable I mean that portraits and sounds should remain as they should be.
Also, when in trouble, please post the contents of your Weidu.log when reporting here.
And welcome to PPG!