Can't change opacity of scene strip in Video Sequence Editor In the VSE, I have a scene strip, but I cannot change the opacity.  It just snaps back to the last value it was keyframed at as soon as I alter it.

(Blender 2.69)
This is already a known issue that is on the To Do list for the VSE.  I'm posting this Q&amp;A because it took me a long time to come across the solution.

As explained in the above bug report, in order to keyframe a scene clip, you must turn off the preview.