I am bothered by unwanted messageboxes, and the 'Calculation keys timer' is not available

[John Brown]

Hello, the Help shows a screenshot in which a checkbox 'Calculation keys timer' is visible;
I don't have that, only the 'Calculation buttons' timer.

I tried changing Calculation modes. It wasn't present in automatic calc mode,
and it  didn't appear when I switched in manual calc mode.

I would really like to get this checkbox. The reason is that if I have a sheet with some formulas like

=RANDBETWEEN(1,2)

And I want to see the values change, then I just hit F9 as many times as I want,

even though Excel is in automatic calc mode. But each time, Fast Excel intrudes and gives me a message box with a time in milliseconds, which I don't want.

So, having seen the 'Calculation buttons' timer and naively thinking it was the only control governing the behaviour of such message boxes, I went and unchecked it. How disppointed I was to find the messages continued, unabated. A bug, I thought. But rereading the Help revealed both the existence and the non-availability (in my case) of the 'Calculation keys timer'; the  non-availability  seems like it is another bug... unless Charles you can shed light?

Regards and thanks

John