When using Excel 2007, I have no problem with the XIRR function.

When I enter the same range of cash flows and dates into Excel 2002 (from
Office XP professional), I get an error (a #NAME error). I've typed
everything in correctly. Why would I have this problem?

Thanks


P.S., for reference, the cash flows and dates are below. The error is from
=XIRR(B1:B18, C1:C18, 0.05)

-32406.00 12/31/2007
-1000.00 1/5/2008
-1000.00 2/5/2008
-1000.00 3/5/2008
926.50 3/30/2008
-1000.00 4/5/2008
-1000.00 5/5/2008
-1000.00 6/5/2008
926.50 6/30/2008
-1000.00 7/5/2008
-1000.00 8/5/2008
-1000.00 9/5/2008
926.50 9/30/2008
-1000.00 10/5/2008
-1000.00 11/5/2008
-1000.00 12/5/2008
926.50 12/30/2008
44406.00 12/31/2008