I had this happen before, usually with big EXCEL files. I change some cells
and a cell that depends on them doesn't change. I have to go into the cell,
take out the last character and put it back in, and then it updates. hitting
F9 alone does nothing.

I am not on manual recalc or iterations. I forgot to try but I bet, if I
saved the file and re-opened it, or closed EXCEL and reopen EXCEL, it would
probably have fixed it too.

Does anyone know why this happens and if it is indicative of an unstable
worksheet, or is it my computer being overloaded?

It's really scary! Thanks for your educated help!
Dean