If I create a table and uses formulas it works well.
It I then decides to change one of the formulas I hit F2 and in the formulabar I make a change to the formula and press enter.
The formula reverts to its earlier state, before I started to change it.
The quick-fix is to open the forumla using F2 and copy it. Press enter. Clear the cell (backspace). Press F2 again and paste the formula and make the change.
Viola it works.
*** This bug has been marked as a duplicate of bug 34565 ***