I’m glad to see I’m not the only one experiencing this issue. Really, really frustrating, especially since Twixtor worked like a champ in Pr CS5.0.
Unfortunately, your workaround doesn’t seem to be working for me. I normally drop a clip into the timeline, add Twixtor, keyframe the first frame of the clip to 100% to anchor the in-point of the clip, and then change to the desired speed in the second frame. Probably not the best solution, but it worked for me in CS5.
I could be misunderstanding what you’re doing. Could you elaborate?