As an addition to this previous post by Coltz, here are two screenshots showing the problem items. The Pirate Harpoon has the icon and model for the Pirate Speargun, and the Pirate Speargun has the model and icon for the Pirate Harpoon.
Character shown is a Norn female mesmer, but I have had this happen with an Asuran male engineer, a Human female warrior, and a Human male elementalist.
