Step to reproduce - Create a new presentation, insert a table - Write some text in any cell - Select the cell, not only the text (not easy) - Delete the text (hit Del ou CTRL + X - Undo (CTRL Z) The Text should be back, it is not You can also fill 2 cells and select the 2 cells, it's easier then to select the cells and not the text
*** This bug has been marked as a duplicate of bug 84513 ***