DataGridView Binding To DataTable

I developed a windows forms app, using VisualBasic in VS 2010. In my form, first I declared a variable as DataTable (Dim VarTable as New DataTable).
Second, changed the DataSource property of my DataGridView (DataGridView1.Datasource=VarTable)
Third, I filled the VarTable in this way: using a resulset from SqlDataReader, i added row by row.

Dim Result As SqlDataReader=CommandSQL.ExecuteReader
Do While Result.Read()
Dim RowToAdd As DataRow
RowToAdd=VarTable.NewRow()
RowToAdd("Code")=Result("Code")
RowToAdd("Name")=Result("Name")
VarTable.Rows.Add(RowToAdd)
Loop

Fourth, after the user changed data in datagridview, I saved the data back to SQL, cleared VarTable (VarTable.Rows.Clear()), and back to top of form to accept a new code. But here, problems begin. When I execute again the whole code described, the datagridview dont show the entire rows, and sometimes crashed with different errors. Solution? Dont fill VarTable row by row. Use VarTable.Load(Result) to populate the VarTable. I don't know why now works, But just I wanted to share this information.