Just played a match and tried to cast Kaya's Guile for its normal 1BW cost and it would not let me, only would allow me to cast for its Entwine (3) cost. Not only this but all of its effects are doubled. Opponents sac 2 creatures, Exile Opponents' graveyard twice, Creates 2 spirits, and gains you 8 life.
Something seriously wrong here, MTGO please look into this and fix it, seems to be a pretty crazy bug.