Its a minor bug, but still thought I'd report it. If two players are standing on the same coordinates and one tries to send a trade request to the other, it won't be sent. You have to be on different coordinates for the trade request to go through. Usually in the real runescape, if the player who sends the trade request is on the same coordinates as the person receiving the request, the sender of the request will move a random block north, south, east, or west of the request receiver and then the request will go through.