If you place a teleporter on the same tile as a wall and an alcove, RTC gives you a warning during compile. That's fine, because in the game if you place objects in the alcove, the teleporting IS performed correctly. However, when the objects land in the target square they become 'ghosts'. RTC still draws them as if they are in the alcove: they are smaller, shaded darker, and drawn lower on the screen and it's impossible to pick them up.
I suspect that this is because there is no direct correlation between the N/S/E/W facing of an alcove and the NE/SE/SW/NW position of objects on a tile.
George, is it possible to fix this so that each facing of a wall translates to a corner of a tile? It opens up possibilities for all kinds of puzzles which can't be built at the moment.

