Macready, I have installed the original UK BG1 (5 CD's) but DO NOT have the Tales of the Sword Coast upgrade. The EasyTutu installshield noted that ToTSC was missing and installed appropriately.
I have tried several times to kill Teyngan, and each time I get the error. I also tried to knock out Algernon, and as the winning blow strikes, I receive the same error. Once again I re-loaded it several times and got the same result.
If it helps, I had Kagain in my party, who was using an axe against Teyngan, although I was using a fist against Algernon - so to speak.
I'm no programmer, but could it be anything to do with a sound file? Maybe ToTSC added/renamed a sound file, which isn't part of the original BG1?
As an aside, I have just gone out and purchased the 'Baldur's Gate 4 in 1 box set' - A 4 DVD multipack with BG1 / ToTSC / BG2 SoA / BG2 ToB. Do you know if EasyTutu has been tested with this? I'll give it a whirl later on and see how it fares!
Thanks for the help so far.