While my char was using the Spell Chaining feature from Enhanced Magic System I noticed that she suddenly couldn't cast one of the spells in the chain, which was odd because she could use it just minutes ago. And when loading from an earlier save she could cast it. It has happened twice. A spell that a minute earlier required Restoration 50 suddenly requires 75. Not sure if it's connected Enhanced Magic System as it sounds unlikely, but it happened both times while trying out spell chains. Anyone who has an idea what might cause it?

EDIT: Nevermind, I switched to the auto cast hotkey in Super Hotkeys. I seem to remember SkyRanger saying it was preferable for some other reason. So now it's even on automatic - and no issue as above either.