Rather than using databound control you can simply load the value of the setting when the settings form loads. It is simple doing it that way, and it works. Otherwise you would have to make a clone of My.Settings: doing _mysettings = My.Settings
is only creating a pointer to My.Settings, not a copy of it.
For example, I have a Form named ChangeConnectionString which has OK/Cancel buttons and a TextBox control named connString:
Public Class ChangeConnectionString
Private Sub bnOK_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnOK.Click
My.Settings.connectionString = connString.Text
My.Settings.Save()
Me.Close()
End Sub
Private Sub bnCancel_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles bnCancel.Click
Me.Close()
End Sub
Private Sub ChangeConnectionString_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
connString.Text = My.Settings.connectionString
End Sub
End Class