Inner join discarded when reports shown from .Net 2005 application

I am using Crystal reports 11 for designing reports - Visual Studio 2005 is the application.

Report preview shows correctly shows the records correctly as in the underlying database
but when shown from Visual Basic 2005, shows records without applying inner join given in the
report - I think using full join (taking one record from first table and linking with all records in the
second table)

Dim ds As New DataSet, adp As New MySqlDataAdapter(sql, con), dt As New DataTable
adp.Fill(dt) : Report.SetDataSource(dt)



MessageBox.Show("Report.Rows.Count: " & Report.Rows.Count) - shows 64 rows
MessageBox.Show("dt.Rows.Count: " & dt.Rows.Count) - shows 16 rows