Trouble writing to App.Config file - vb.net

Question

Having issues reading/writing to App.config.
The code I have below I took from the MSDN article on (AppSettingsSection Class)
http://msdn.microsoft.com/en-us/library/system.configuration.appsettingssection%28v=vs.100%29.aspx
I am successfully able to read the App.config file and get/use the values and it responds correctly if I change the App.config file to get the new values.
However, in this (from MS page) I add a new entry and change a value on one of my initial entries. It appears to change it, does not error in saving it, but does not write it to the file so the next time I run, I am back to my initial values in App.config.
Can someone show me my erroneous ways?
TIA!
Imports System
Imports System.Collections.Specialized
Imports System.Configuration
Imports System.Text
Imports System.IO
' IMPORTANT: To compile this example, you must add to the project
' a reference to the System.Configuration assembly.
'
Module Module1
Sub Main()
Dim KeypairHolder As String = Nothing
' Get Configuration File as config object
Dim config As System.Configuration.Configuration = ConfigurationManager.OpenExeConfiguration(ConfigurationUserLevel.None)
' Create a unique key/value pair to add to the appSettings section.
Dim keyName As String = "DateTimeStamp Number " & config.AppSettings.Settings.Count + 1
Dim value As String = String.Concat(Date.Now.ToLongDateString(), " ", Date.Now.ToLongTimeString())
' Create appSettings as object
Dim appSettings As System.Configuration.AppSettingsSection = config.AppSettings
' add the new key and value
appSettings.Settings.Add(keyName, value)
' save and refresh the values
config.Save(ConfigurationSaveMode.Modified)
' Force a reload in memory of the changed section.
ConfigurationManager.RefreshSection("appSettings")
' Get keys
Dim kAll() As String = appSettings.Settings.AllKeys()
' Build string to display
For Each key In kAll
KeypairHolder = KeypairHolder & key & ": " & appSettings.Settings(key).Value & vbCrLf
Next
'Display
MsgBox(KeypairHolder)
' Change a value
appSettings.Settings("CustomKey").Value = "Changed Value"
' Resave and get and display
config.Save(ConfigurationSaveMode.Modified)
ConfigurationManager.RefreshSection("appSettings")
kAll = appSettings.Settings.AllKeys()
KeypairHolder = Nothing
For Each key In kAll
KeypairHolder = KeypairHolder & key & ": " & appSettings.Settings(key).Value & vbCrLf
Next
MsgBox(KeypairHolder)
End Sub
End Module
' appSettings Section of my App.Config file
' <appSettings>
' <add key="UsernamePassword" value="BobsUsername:BobsPassword"/>
' <add key="CustomKey" value="ConfigApp Value"/>
' </appSettings>

Answer 1

Right click on the app.config file in your solution explorer window and select the Properties option. Ensure that the Copy to Output Directory property is NOT set to Copy always.