Are you able to share the FLA file?
I've attached here.
The frames in question are the ones that were highlighted on the "J morph" and "K morph" layers, correct?
Classic tweens and shape tweens are not supported on tween layers. They cannot be created on these layers, and if they're dragged or pasted there, they'll turn static (an undo is needed to move them back).
So my guess is that it may have been done before the save, as I can't imagine how that would have occurred between saving and reopening. The fix would be to put those two shape tweens on their own layers (which is a preferred practice anyway) and see if that fixes things.
Hope that helps,
Oh, yeah. I forgot that shape tweens have to be in a separate layer.
I did as you suggested and now the shape tweens survive the save. Thanks!