Collectible Card Game Headquarters

Describe the Bug:
1) Return to Dust doesn't let you pick a second target except during your own main phase.
2) If you pick a second target during your main phase, it doesn't let you decline to exile it.
3) If you click "cancel" when prompted for the second target, it doesn't cancel the spell, instead interpreting it as "done" (for which there's no button).

Which card behaved improperly?
Return to Dust

Which update are you using? (date, name)Which type? (duel, gauntlet, sealed deck)
Dev e9d990e.

What exactly should be the correct behavior/interaction?
Whether to exile the second target isn't a targeting choice, so the choice is made during resolution, not announcement.

Ruling 9/25/2006: Regardless of when Return to Dust is cast, its controller may choose one target or two targets. It can always be cast even if there's only one legal target. If it's cast at a time other than its controller's main phase and a second target is chosen, nothing will happen to that target.

Are any other cards possibly affected by this bug?

Korath wrote:3) If you click "cancel" when prompted for the second target, it doesn't cancel the spell, instead interpreting it as "done" (for which there's no button).

I think there are lot of cards with cancel = done problem.