i have this procedure that fill my wingrid but i have an intermitent problem, if i ran my process 30 times only 2 or 3 times will throw the following error, any idea on what is wrong with my code or is a wingrid problem?

Error

not alway same error, but intermitent, all of them had results the store procedure

1)   ************** Exception Text **************
System.ArgumentException: An item with the same key has already been added.
   at System.ThrowHelper.ThrowArgumentException(ExceptionResource resource)

2) ************** Exception Text **************
System.ArgumentOutOfRangeException: Index was out of range. Must be non-negative and less than the size of the collection.
Parameter name: index

Code

 Private Sub LoadResults(ByVal StrFromDate As String, ByVal StrPercentage As String)
        Dim DS As DataSet = New DataSet

        Try
            QueryHst = False
            DS.Tables.Clear()
            Application.DoEvents()

            DS.Tables.Add(Conn.GetData("exec sp_DataGetPriceError " & _
                                    "@FromDate = '" + StrFromDate + "', " & _
                                    "@Percentage = " + IIf(StrPercentage = 100, "1.0", "0." + Format(CInt(StrPercentage), "00").ToString)))

            'Show the grid
            dgv1.ResetLayouts()
            dgv1.SetDataBinding(DS, "table1")

            ShowAnimation(False)

        Catch Ex As Exception

            Conn.LogError(gUser.pUserID.ToString, My.Computer.Name.ToString, "Frm Price Error", "Load Results", "value change", "1", Ex.Message.ToString)
        End Try

    End Sub

store procedure always return a value.

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