Folks - For those of you who care, I worked with Microsoft support yesterday,
and apparently the problem is a compatibility conflict between old Excel and
2007 Excel. I was using 2007 Excel, but the saving the files in the 2003
version of Excel. Since the XIRR and XNPV formulas need the analysis tool
pack in old Excel, but not in new Excel, this apparently created a conflict
and the formulas, and other parts of the spreadsheets, became corrupted. The
solution, (I hope), was to repair the files, and save them as Excel 2007
files. I still have to manually re-enter the formulas, but now, hopefully,
they will be stable and will not become corrupted.

"Terry McCoy" wrote:

Ron - I appreciate your help, and I think you are on to something. The
formulas link to another spreadsheet in the same workbook. One of the links
is not working when I re-open the workbook, it also has "=N/A" in it rather
than the link. I just re-established the link and closed and re-opened the
workbook, and it went right back to "=N/A". I am also getting a message when
I open the workbook of "File Error: Data may have been lost" which may be at
the root of this problem.

I would welcome any comments or suggestions. Thanks.

"Ron Rosenfeld" wrote:

On Thu, 17 Apr 2008 10:18:03 -0700, Terry McCoy <Terry
wrote:

I have an issue with the XIRR and XNPV functions in Excel 2007. The formulas
seem to be operating properly, but when I go back into the spreadsheet after
closing it, the cells where the formulas were now say #N/A. I have not made
any changes to the spreadsheet. I do not have the analysis toolpak checked
on the add-ins, but I understand that these functions are integral to Excel
2007, so I should not need the toolpak. I would appreciate any help anyone
can give me with this issue. Thanks,

Terry McCoy

#N/A indicates that a value is not available to the function or formula.

Could it be that some of the source data is not in an available workbook, at
the time you reopen the workbook containing the function?
--ron