Here is my formula:
=SUMPRODUCT(--('Call Summary.xls'!$I$10:$I$5000=C78),--('Call
Summary.xls'!$D$10:$D$5000<"lastname, firstname"),--('Call
Summary.xls'!$L$10:$L$5000))

This works fine; but when I change the "lastname, firstname" to this;

=SUMPRODUCT(--('Call Summary.xls'!$I$10:$I$5000=C78),--('Call
Summary.xls'!$D$10:$D$5000<C78),--('Call Summary.xls'!$L$10:$L$5000))

It sums all the data including the data I do not want referenced in
cell C78...


Does anyone know why??


Thanks,

Hans