Valorin, I had the same problem running 5 wow clients off of one wow folder with symbolic links. I agree it may have had something to do with the update while playing feature that they have implemented. I moved to 5 totaly separate folders on 5 different hard drives and the crashes have gone away. I haven't gone back to my sym links yet just because i was too frustrated with have 2 of my clients crash on every pull i made.