First printings of this card said, ". . . can only be resurrected if another summon has been killed this turn." and " . . . Place Skeleton King on a spot where a summon has been killed this turn . . .". All the instances of the word "turn" are now "round".
Skeleton King is getting its second errata in two sets. Its Resurrect ability is now becoming a Resurrect Beckon ability; it functions the exact same but is now a beckon ability like every other summon.