Cannonballs keep getting fired at my character in Borean Tundra

Just landed in Northrend and I got this weird visual glitch where cannonballs keep getting fired at my character (and other NPCs).

https://www.youtube.com/watch?v=tzbk7maiAwU

It's killing my FPS and I'm not sure how to fix it, any suggestions would be appreciated it.

bump, same happened to me, its really annoying

same here..its distracting,frustrating and yeah its keeping my fps low :/

It's still happening