Well, to conform this diagnose, you would actually have to post the setup-bg1Tutu.debug file if you installed the bg1Tutu... I don't know about the EasyTutu...
But I am pretty sure the BGMain.exe was not patched right, so if you would like to do it yourself, you need the archive I have attached into
here, extract it to the game folder, run the file and set the number to 1...
Now, you of course have to have the UAC turned off(during the installation or launch the program as the Administrator) and the game needs to be in the non-Program Files sub-folder, for the patching to actually take effect...
Imoen is that level because the player character is that level, as are a lot of the other NPCs in the game... that's original BG1 game behavior.