During the first mage guild quest when you go to the cave and help a guy find 4 magic artifacts once I pick up the necklace and he babbles as soon as I use a spell on the "door" my game locks...this has happened twice on that same part. Anyone else have this issue?

It happened for me too for 20 min ago, the game have been runnin great for 2 days before I got to this cave. I have a i7 980x, 6 gb ram, asus matrix gtx580 platinum (beta drivers 285.79), win 7 64 bit sp 1 home premium (swedish).