And on further testing, this happens with the default Fire skill in the demo too!
EDIT: And Slash too. Oh, and the Ice 1/2/3 and Blizzard spells in the demo have no range whatsoever except the tile directly on top of the user, neither does the Silence skill, or Paralyze, or Fire III, or Flame II, or Quake I. But for whatever reason Flame I works fine...