Hi people and guests of excelexperts!

I'm having an issue >_<, I am trying to use a SUM* formula with these conditions:

=SUMIF(Sheet1!D:D;B9;Sheet1!B:B)

Where "B9" equals a name "XXX" in letters.

In the "range" (Sheet1!D:D); I want a formula to check the name "XXX" in the whole D column and where it matches the criteria "B9" make a sum of numbers based on the sumrange of Sheet1!B:B.

What I do not understand is that the formula I am using (SUMIF) always returns 0 as valor and it should not, what am I doing wrong?

Extra details:

In the B column I have many types of cells (Date, Text, General, Number) as well with the D column. Are these many kinds of cells a problem for the SUMIF function? I've read many websites saying that the SUMIF only takes the numeric cells, but it seems there is a problem or I do not know what I am doing wrong.

Thanks for your support :)...