about arrow attack, this is what i have found:
Friends with linux versions have no trouble casting the spell so it seems to affect only the windows version.
You dont need to cast anything for the client to crash, if you are seeing somebody casting it, it crashes too!

just happened to me right now.
Seems that the animation for the spell is wrong, not for the casting, the spell, it does not show the arrow but an increasing bright white light, AFAIR this animation belongs to another spell.
Hope that helps locating the problem.
Ranust