SMTP cripples my attachments

Sub Process_Globals
   'These global variables will be declared once when the application starts.
   'These variables can be accessed from all modules.
   Dim sm As SMTP
End Sub

Sub Globals
End Sub

Sub Activity_Create(FirstTime As Boolean)
   If FirstTime Then
      sm.Initialize("xxx", ... , "sm")
   End If
End Sub

Sub Activity_Resume

End Sub
Sub Activity_Click
   sm.AddAttachment(File.DirAssets, "20121114151502os2.txt")
   sm.Body = "test"
   sm.To.Add("xxx@xxx.com")
   sm.Send
End Sub

Sub SM_MessageSent(Success As Boolean)
   Log(Success)
End Sub