COUNTIF Bug in Excel 2003

1) Open a new workbook.
2) In cells A2, A4 and A6 enter the word "dog".
3) In cell B1 enter the formula:

In Excel 2003, I get 65533.
In Excel 97, 2000 and 2002, I get 3 (for the three blank cells between A1
and A6)

Thinking that it might be a corrupted Excel 2003 install, I asked a friend
to check his results--and he confirmed my experience. I'm using version
11.6355.6408 SP1.