Mark Neuffer wrote...
Thanks for your reply. Unhappily, I think this treatment of a multi-modal
array is erroneous from a statistical standpoint. Any thoughts about how I
can raise this with Microsoft? Mark
....

It's not erroneous. MODE returns a *single* value. If there are
multiple modes, Excel's MODE function returns only one of them, the
first one found. That particular behavior isn't documented in online
help, but it's well known. The value that it does return most
definitely is a mode, so it's hardly a bug that MODE returns different
values depending on the order of the data.

If you want all modes, you need to use multiple MODE calls. For
example, if your data were in a range named d and the first mode found
would be in cell G1 and the next in cell G2, etc, try these formulas.

G1:
=MODE(d)

G2 [array formula]:
=MODE(IF((COUNTIF(G$1:G1,d)=0)*(COUNTIF(d,d)=COUNT IF(d,G1)),d))

Fill G2 down until the formula returns #N/A.

Again, not a bug, just a poorly documented limitation of functionality.