This is a re-send due to no reply before.

I am getting a 0 as my result, consistently. I have three columns. If
$A$n=$A$(n-1), I want to add the value in $B$(n-1) to $B$n. I incremented
the SUMIF value by extending the formula from C2 all the way down.

=SUMIF(b2:b3,A3=A2,b2:b3)

What might keep the function from working properly?
--Dave.