I have a user with a quirk in his Excel that seems to turn off the Automatic Calculation. We have tested several scenarios and cannot determine why this happens. I looked through the built in tool bar customization options and didn't see one for this function. Is it possible to create a custom toolbar item that indicates whether Auto or Manual Calc is turned on and gives him the option to either switch or turn on Auto Calc (similar to the Protect Sheet/Unprotect Sheet command available in the built-in tool bar customization options)?