Comment 2 for bug 285966

Here's an example of a common situation caused by that "feature" :-)
https://answers.launchpad.net/inkscape/+question/66551
That was caused by an invisible object with a filter. It's quite difficult to address the origin of this kind of problems for the novice user.
I think we should change the importance of this report from "wishlist" to "bug". Technnically it's not a bug, but it brings several problems and no advantages.
I'd add that an object with 0% opacity should have filters de-activated if its opacity is 0. It's pointless to include an object in the redrawing if it isn't visible.