I believe sometimes items aren't removed from the market after removal by the seller (not sure if it affects purchased). Clicking the item in the market produces the error:
[12:28:34 WARN]: [GlobalMarket] Null IMarketItem in InventoryClickEvent with position 5 (raw: 5) in interface Listings, should have an ID of 5864.
Last ender pearl in this screenshot (searched for seller's username):
I believe sometimes items aren't removed from the market after removal by the seller (not sure if it affects purchased). Clicking the item in the market produces the error:
Last ender pearl in this screenshot (searched for seller's username):
http://i.nentify.me/Ee5rg2gN.png