Excel takes the Calculation mode each session from the settings on the first
workbook opened in that session.

i.e. If you saved Book1 with calc mode in manual and opened it first, calc
mode would be in Manual for all subsequently opened workbooks.

If you saved Book2 with calc mode in auto and opened it after Book1, Book2
would be in manual mode(Excel ignores the auto calc mode in this case).

If you close Book1 before opening Book2, Book2 will be in auto calc mode.

Confusing enough? <g


Gord Dibben MS Excel MVP

On Fri, 23 Apr 2010 18:20:01 -0700, PA Valley <PA
wrote:

All of a sudden the formulas in a cell are not updating. I have read the
posts rid the fix and nothing happens. Only by going to the cell, clicking on
the formula, hit return does the cell update. This happens whether there are
multiple worksheets or just one. Very frustrating