Storing disconnected Dataset

[mansii]

Framework 1.1

Working Environment:
- Heavy data traffic
- Sudden electricity shut down

Strategy:
- Store current documents in local machine
- Save it to database server when user finished keying all documents.

Read all local tables and store them in a local dataset:

Dim LeftLocalSet As DataSet
LeftLocalSet = New DataSet("LeftLocal")
Dim ntbl As DataTable
Dim cmd As OleDb.OleDbCommand
Dim TblNm As String
Dim da As OleDb.OleDbDataAdapter
Try
   For i As Integer = 0 To 2
      TblNm = "Table" & i.ToString
      ntbl = New DataTable(TblNm)
      cmd = New OleDb.OleDbCommand("SELECT * FROM " & TblNm, LocalDataConn)
      da = New OleDbDataAdapter(cmd)
      da.Fill(ntbl)
      LeftLocalSet.Tables.Add(ntbl)
   Next
Catch ex As Exception
   MsgBox(ex.ToString)
End Try

Try
   Dim Result As Integer = _
      UploadLeftOver(LeftLocalSet)
Catch ex As Exception
   MsgBox(ex.ToString)
End Try

Public Function UploadLeftOver(ByVal ds As DataSet) As Integer
   Dim c As OdbcCommand
   Dim ret As Integer
   Dim DA As New OdbcDataAdapter
   Try
      If Not rDataConn.State = ConnectionState.Open Then rDataConn.Open()
      Dim DS2Upload As DataSet = ds.Copy
      For Each tbl As DataTable In DS2Upload.Tables
         c = New OdbcCommand
         c.CommandText = "select * from dba." & tbl.TableName
         c.Connection = rDataConn
         DA = New OdbcDataAdapter
         DA.SelectCommand = c
         Dim cmdbldr As New OdbcCommandBuilder(DA)
         DA.DeleteCommand = cmdbldr.GetDeleteCommand
         DA.UpdateCommand = cmdbldr.GetUpdateCommand
         DA.InsertCommand = cmdbldr.GetInsertCommand
         ret += DA.Update(tbl)
      Next
   Catch ex As Exception
      MsgBox(ex.ToString)
   Finally
      DA = Nothing
      If Not rDataConn.State = ConnectionState.Closed Then rDataConn.Close()
   End Try
   Return ret
End Function

Result:
- No error occurs
- No records updated

I used to manually loop through all records and update/insert it manually. Now I want to start using DataAdapter.
Did I miss something here?