I'm baffled!

https://dl.dropboxusercontent.com/u/...m-Puzzle-1.jpg

Regardless of what format I use, that SUM gives the strange result
shown.

I then re-typed all those numbers into another column, P, and now the
SUM gives a different but still wrong total equal to =SUM(O8:O16)
instead of =SUM(O3:O16).

Then I added a fresh worksheet and typed in a few arbitrary numbers
into a column and SUM worked correctly.

But when I copy/pasted the original 14 cells D3:D16 into the new
worksheet and summed them, once again I got 38!

It may be relevant that when I choose the SUM tool, Excel 2000 first
sometimes selects a horizontal default range. When I somehow get it to
select a vertical range, it chooses a default of only the last 9 cells
(which don't give a total of 38 anyway). I then extend it upwards to
the full 14 cells, but still get a total of 38.

What can possibly have caused this weird behaviour please?

If it's relevant, the original data entry was probably formatted as
either General or Text. I've changed it many times since, but it makes
no difference.


--
Terry, East Grinstead, UK