Pelo que eu descobri, CTRL + F9 não recalcula a planilha, ela minimiza a pasta de trabalho, então talvez você esteja apenas pressionando as teclas erradas?
F9 Calculates all worksheets in all open workbooks.
SHFT + F9 calculates the active worksheet in Microsoft Excel.
CTRL + ALT + F9 calculates all worksheets in all open workbooks, regardless of whether they have changed since the last calculation.
CTRL + ALT + SHFT F9 rechecks dependent formulas, and then calculates all cells in all open workbooks, including cells not marked as needing to be calculated.
CTRL + F9 minimizes a workbook window to an icon.
fonte keyxl.com