Does this file act the same on different computers?
If not, then the problem is probably with the computer where it acts up.
If so, then one possibility might be that a macro is turning off
calculations as the workbook is opened......try starting the file with macros
disabled to see if this might be the cause.......

hth
Vaya con Dios,
Chuck, CABGx3



"Jon Martin" wrote:

Hi,
We are using Office 2003, and use many WB's, last night one particular WB
when cells were changed would not update simple formulas. I have checked that
the calculation tab is set to automatic as I know this can cause this. Even
in the WB pressing F9 at the time would also not work.
Don't know if it's any coincidence but we have just upgrade to Windows XP
operating system.
Any suggestions out there.
Many thanks.