Problem with an Aggregate Fonction and Filtering in a DataSet

[Jenny C.]

Hi

I am trying to do a SUM on a DataSet column with the following code

// ds is the DataSet that I need to calculate data fro
String filter2 = "EmpNo = " + this.EmpNo + " AND WEEK_ENDING >= '" + MyDateTime.Date.ToShortDateString() + "'"
float totalGross = Convert.ToSingle(this.ds.Tables["Earnings"].Compute("SUM(GROSS)", filter2))
float totalEarn = Convert.ToSingle(this.ds.Tables["Earnings"].Compute("SUM(Earns)", filter2))

Here the problem: it doesn't calculate the good sum: if I have three lines with the same WEEK_ENDING it only keeps 2 lines
so I get the SUM if two lines only. When I looked closely I saw that the GROSS amount for 2 of the lines were identical
So I changed one of the GROSS amount in the DB to make sure that the 3 amounts were different, and then it worked perfectly
What am I missing there? Why is ADO is filtering out one of the line (I think that the filtering might be the problem here...)

Thanks a million for your help

Jenn