"Jon Peltier" wrote in message

Your problem seems to be those two blank X values. However, I used
different data:

Normally a set of XY values would not include a Y without a corresponding X,
even if the Y was zero - ?

I think easier to see what's going on to start with a small single XY series

x y
4 0
0
0
4 0

Change each of the values in turn, including the missing X values. Also
toggle 'Show empty cells as Gaps/Zeros'

If anything maybe the 2007 chart displays more logically than the 2003
version. Even so, the data should not include an unmatched XY pair.

Regards,
Peter T