You will need to ensure that those files are saved in Excel 2007
format (with an extension of .xlsx) rather than .xls files that just
happen to be running within XL2007. Also, ensure that your formula
references are to [filename.xlsx] rather than [filename.xls].

Hope this helps.

Pete

On Jul 22, 7:51*pm, Ed Hoag <Ed wrote:
I am getting an error message in Excel 2007 that advises me that the file
version cannot contain formulas that reference cells beyond the worksheet
size of 256 columns or 65,536 rows. *Both the worksheets involved in the
function are in Excel 2007