Android Question FTP.Upload never fires UploadCompleted with big files (>2MB)

Cursor finalized without prior close()
and 
sqlite returned: error code = 17, msg = statement aborts at 43: [UPDATE Master SET RefDateModified=? WHERE FullPath=?] database schema has changed

Sub Process_Globals
   Dim FTP As FTP
End Sub

Sub Globals
End Sub

Sub Activity_Create(FirstTime As Boolean)
   If FirstTime Then
     FTP.Initialize("ftp", ...)
     FTP.UploadFile(File.DirRootExternal, ...)
   End If
End Sub
Sub FTP_UploadProgress (ServerPath As String, TotalUploaded As Long, Total As Long)
   Activity.Title = TotalUploaded
End Sub

Sub FTP_UploadCompleted (ServerPath As String, Success As Boolean)
   Log("Completed: " & Success)
End Sub

  If okexp = "X" Then 'export solo se ci sono record
       File.WriteList(sdRoot,Nfile,List1)
       List1.Clear   
       TxtLog.Text = "Creato File "&Nfile&Chr(10)&TxtLog.Text
       If FTPMode="F" Then    'connessione FTP
         TxtLog.Text = "Connessione FTP "& FTPHost &"(" &FTPPort &") in Corso..." &Chr(10)&TxtLog.Text
         TxtLog.Text = "Invio File "& Nfile &Chr(10)&TxtLog.Text
         FTP.UploadFile(sdRoot, Nfile, True, Nfile)
       '   Do While okexp <> "S" AND okexp <> "N"
       '     DoEvents
       '   Loop
       End If
       ProgressBar1.Progress = 100
       LblStatus.Text = ProgressBar1.Progress &"%"
       Msgbox2("Esportazione completata!",Main.nomeprog,"","Ok","",LoadBitmap (File.DirAssets, "warning_small.png"))
     Else
       Msgbox2("Non ci Sono Dati da Esportare!",Main.nomeprog,"","Ok","",LoadBitmap (File.DirAssets, "warning_small.png"))
     End If

Sub FTP_UploadProgress (ServerPath As String, TotalUploaded As Long, Total As Long)
  Dim s As String
  s = "Uploaded " & Round(TotalUploaded) & "B"
  If Total > 0 Then s = s & " out of " & Round(Total / 1000) & "KB"
  Log(s)
   LblProgress.Text = s
End Sub

Sub FTP_UploadCompleted (ServerPath As String, Success As Boolean)
  Log(ServerPath & ", Success=" & Success)
   ProgressBar1.Progress = ProgressBar1.Progress + 25
   LblStatus.Text = ProgressBar1.Progress &"%"
   Msgbox(Success,"esito")
   If Success = True Then
     TxtLog.Text = "File "&Nfile&" Inviato con Successo!" &Chr(10)&TxtLog.Text
     Dim Answ As Int
     Answ=Msgbox2("Elimino dal Tablet il File Inviato?",Main.nomeprog,"Si","","No",LoadBitmap (File.DirAssets, "warning_small.png"))
     If Answ=DialogResponse.POSITIVE Then
       File.Delete(sdRoot,Nfile.trim)
     End If
     ContrassegnaRecord
     okexp="S"
   Else
     ProgressBar1.Progress = 100
     Msgbox2("Errore nell'Invio File "&Nfile&"!",Main.nomeprog,"","Ok","",LoadBitmap (File.DirAssets, "warning_small.png"))
     File.Delete(sdRoot,Nfile.Trim) ' cancello il file dal tablet
     ' chiudiamo la connessione
     FTP.CloseNow
     Timer1.Initialize("Timer1",4000)
     Timer1.Enabled=True
     okexp="N"
   End If
End Sub