Can't cast Conflagrate for X=0

[Doyle524]

When trying to get Conflagrate into my graveyard so I can cast it for its flashback cost, I can't cast it for one red mana. I choose to cast it, pay the cost, and it just disappears from the game. It doesn't hit the stack, it doesn't go to the yard, it isn't exiled, it just doesn't exist; I have 5 cards in hand, none in GY or exile, and 53 in library if I do that on the play turn 1.

[Hanmac]

should be fixed in r31995.

while fixing it i found a bigger problem when casting it without paying the mana cost.
(now i need to check more cards where thats the problem)