Regular cells seem to move fine, but they move under the section headers which remain static. Behavior can be seen in the sample project.
I believe that _layoutSectionHeaders: is immediately resetting the frame of the section header.
Could you describe this behavior with an image? I think this is how they're designed to work- section headers float above the cells when they're in the plain table view style.
Here you go
Dragging cell #2 from section 1 to section 0 pushes cell #24 in section 0 to be under the section one header. (you can see the text box from cell 24, even if you can't see the text).
This bug is (partially) fixed in pull request 114. I haven't had enough time to look into it much deeper, I'm afraid.