MS Excel 2010 is not updating formulas. For instance, I have this formula in cell `D2`

:

```
=A2 + B2
```

If I put data in `A2`

and `B2`

, `D2`

does not show the result.

However, if I enter values in cells `A2`

and `B2`

first **BEFORE** I enter the formula in `D2`

, it shows the result, but the formula only seems to work "once." If I change the values in either `A2`

or `B2`

, `D2`

does not get updated.

Can you help me ?