1.The passive that doesn't work is Molten Core http://www.db.pandawow.me?spell=122351#changelog
2.The part when it gives you stacks of Molten Core works , but when to use 2 of them with Soul fire ( That means 100% cast reduction on Soul Fire , in conclusion it should be instant cast) , sometimes it is casted with normal speed , sometimes it use only 1 stack of Molten Core and sometimes it is instant , but very rare.The only way I could add a proof is a video , but I hope other players will approve and the video wouldn't be needed.
3.When you have 1 stack of molten core , it should reduce the cast time by 50% , and when you have 2 stacks of molten core , it should reduce the cast time by 100% , that means instant casting it ( like Pyroblast with Hotstreak passive). Proof : When Shadowflame or a Wild Imp deals damage you have an 8% chance to trigger Molten Core.
Molten Core
Reduces the cast time and mana cost of your next Soul Fire spell by 50%.
4. 30/03/2014
5.The realm is Pandawow 100x
6.Priority of the problem should be like 9/10 or 8/10 because almost no one plays demonology because of this bug.I think like 1/3 from Demonology warlock burst comes from instant Soul Fire.