Hey Roxanne, I have ran into a continuing/repeating spell issue that causes the final fight with Melissan to freeze and eventually exit out. Some time ago I had the same issue with the Mold Golem and I discussed the problem with Paula on the Beamdog Forums. My Son discovered that the Mold Golem would infinitely cast the Fireball spell, causing the screen to become choppy and eventually freeze and exit out. The Melissan issue is the same, however this time Melissan continually casts "Taint of the Slayer" against whoever she's fighting, eventually causing the game to slow down, freeze and eventually exit out.
I've tried the fight a few times, with the same result. I don't know if this has anything to do with it, but it always seems to happen with I have two of the Bhaalspawn left, then she starts casting or using Taint of the Slayer.
Do you have any recommendations?