I have 11 days played on my hunter. I have used throwing knives [u]ALOT[/u]. To me they travel in a straight line, but the perspective can make you suggest otherwise. You must remember that you are leading your opponent. Therefore, if they strafe back into the knife it may look as though it has curled. I assure you, they don't curl. Almost all of my play time on my hunter is PvP.