This could be a duplicate of CONF-25880. This issue is a real pain for us because we use tables with with expands for all sorts of things.

Steps to recreate:
1. create a table with a few columns
2. in one of the cells, add an expand
3. use the copy row button on the toolbar
4. create a new row and then click in it
5. use the paste row button.
6. result: the row is pasted incorrectly (see attached screen cap).