I inserted a combo box form control in a cell and found problems with
changing the value.

Another cell on the worksheet contains a formula using the value in the
combo box.

When I selected a new value in the combo box and recalculated the formula it
used the old value in the combo box rather than the new one.

I noticed that when I used the arrow keys to navigate back to the cell
containing the combo box the formula bar showed the old value, even though
the combo box in the cell showed the new value.

Am I doing something wrong, or is Excel not behaving as it should?