Why does this not work:

=SUMPRODUCT(--(CaseData!$X$2:$X$1000="Yes")*--(CaseData!$C$2:$C$1000=--DATE(2006,1,1)*--(CaseData!$C$2:$C$1000<=--DATE(2006,3,31))))


and this does:

=SUMPRODUCT((ISNUMBER(SEARCH("Yes",CaseData!$X$2:$ X$2000)))*(CaseData!$C$2:$C$2000=DATE(2006,1,1))* (CaseData!$C$2:$C$2000<=DATE(2006,3,31)))

I am trying to get the total number of Yes' in column X if the date is
between 1/1/6 and 3/31/6.