Timewarp only showing half the clip at 50%

I've read a few responses and seen that people have doubled the clip and used pre-comps, and I'm just in a state of disbelief that I have to do these things.  It seems like I should be able to apply Timewarp at 50% to a 7-sec clip, and the clip should become a 14-sec clip.  This is a little too easy for it not to work.

Any suggestions out there?

Thanks, Ron