Tab list headers and footers stay even when rejoining a diferent server

when i enter to this server-side modded server ip: play.cubecraftgames.net tab list has a header and a footer (http://gyazo.com/d246112b4402151dda2a4a933897f6b1)
it's not fake player names, bcos it's in a different "box", the player one has lighter background

the bug is that when i log off, and log into another totally different server, or a vanilla one, it is still there! (http://gyazo.com/0e1b0a2e882530591248a7923f966b7b)