#6 Nether toggling can move the player to an area with no map

[CJ Kucera]

Right now the Nether toggle will attempt to put you in the equivalent spot, as if you had travelled via a Portal. Unfortunately this can land you outside the actual known-map area, so you'll be presented with a black screen. home/end/ins/del can be used to warp back to known territory, of course, but it's hardly ideal.