Hi everyone

I have been using excel to track invoices ect for quite a while now, and
today without any warning (or changes to settings etc), the formulas dont
seem to work over the entire spreadsheet, unless i click on the individual
cells highlighting the cells that the formula uses, then press enter. All
the previous entries that i have done are fine, they have not changed, but if
i go back and try to update a number, the end result will not change
automatically like it used to. is there anything i can do about this? Is in
a known problem?

thanks