If I apply a drop shadow and save the image, it's pretty much permanent. I am unable to later remove the shadow. Even if I select a shadow color of white, and a weight of zero, it remains. And weirdly, I can't change a shadow to a saved image. If I start with 8, and Apply, I get 8. If I go back and change to 15 and Apply, it's as if I have 8 AND 15! In other words, if I applied 15 to a virgin image, it would look different than if I started with 8 and then changed to 15. In the doc, it says the way to undo a shadow is to literally use "Undo". Not very useful if you want to go back to an older image. By the way, I'm saving as both .sng and .png. Is this the intended behavior?