I have multiple formulas set to add various cells.
There are values in the cells but the SUM function brings back a value of
ZERO.

For Example:

Cell A1 =SUM(A2:A5)

Cell A2 24
Cell A3 24
Cell A4 24
Cell A5 24

Cell A1 shows ZERO.

If I double click or hit the F2 Key followed by the Enter Key, then the
Formulas will see the value in the cell I edited. I tried changing the cell
Format type. I even did Copy-Paste Special-values, using multiple format
types.

I verified that Auto Calculation is ON. I have not had this problem before.
and since my Macro are addind Hundreds and sometime thousands of cellls....

Your assistance in this matter will be greatly appreciated.