Formulas Do Not Work Automatically

[tornadowatch]

I have been using excel in XP Pro. Edition for several months. Just recently when I enter new data in the cells, the result does not change. The formula is correct but doesn't work. I can enter the exact same formula back in the cell and it works fine, but will not update when numbers in the cells are changed. What the heck is up with that?

 

[tes1900]

I too am having the same problem. The division function and the average function have been noticed not working. I checked to see if it was moved from automatic and it is stills et on automatic. So far it seems that any function that involves division doesn't work. No one else has ever used my computer except remotely - but excel was never used, although it might have been open at the time - not sure.
I can do a manual of division but don't know how to set up a problem in average


Update: I tried control-alt-F9 and it was of no help