Try pressing L to disable all cheats for the game.Okay, got cheats working now. Except...once I "save" the cheats I want to use, I can no longer deselect them, which is weird. For example, I enabled a Wild Pokémon Modifier cheat for HeartGold, and now I don't want it activated - when I go back to TWiLight++ and go to the cheat and press A, the cross to the left of it remains.