XL2003. I have a simple little workbook where I add six numbers to a little
column of prepared cells every month in rows 5:9, column R one month, S the
next and so on. The sixth number is the received total, so I have a check
further down that adds (say) R5:R9 and should naturally get the same answer
as that sixth one in R10. The trouble is that as soon as I tab out of that
sixth cell the check sum formula morphs to SUM(R5:R10). Why?

I catch the error here, but I'm nervous that it might happen elsewhere in a
not-so-obvious way.