Just noticed an error come up when two trade windows are opened at the same time (as in myself and another player both initiated a trade window at the same time). The trade I initiated failed but the trade that the other person initiated was somewhat successful. My log shows the trade was cancelled though but I didn't get the items back nor did I get the item that was being traded to me. The other player didn't get the item they were trading back either. It disappeared into the pixels somewhere.