[2005] Where is my problem

[Bongo]

Greetings,

When I try to run this code i get most time a exception in the part
Catch exc As Exception
It is a IOException
The Process can not access the file D:\views\pledlm_view\applications\ktr\source\KTR Client\KTR Client\bin\Release\KTR Client.exe.config because another process is using it.

Background:
1. The app = not MutliThreating
2. I use the routine to add a new value in to the App.config

For easier understanding i posted the whole class as zip to the thread

Private Function LoadConfigSource() As String
 
        Dim dllPath As String = System.Reflection.Assembly.GetExecutingAssembly.Location
        Dim filename As String
 
#If DEBUG Then
        '--> if debug app.config file is not in bin folder
        Dim strTemp As String = Path.GetDirectoryName(dllPath)
        strTemp = strTemp.Substring(1, strTemp.Length - 1)
        strTemp = strTemp.Substring(1, strTemp.LastIndexOf("\bin\"))
        filename = strTemp & "app.config"
#Else
        '--> get the name of the calling assembly (in the testcase TestConfigProvider) and built the path of the config file in release mode
        filename = Path.GetDirectoryName(System.Reflection.Assembly.GetExecutingAssembly.Location) & "\" & System.Reflection.Assembly.GetEntryAssembly.GetName.Name.ToString & ".exe.config"
#End If
        configSource = New XmlDocument
 
        Dim cstream As Stream
 
        Try
            cstream = File.OpenRead(filename)
            configSource.Load(cstream)
 
        Catch ex As FileNotFoundException
            Throw ex
        Catch exc As Exception
            Throw exc
        Finally
            If Not cstream Is Nothing Then cstream.Close()
        End Try
 
        Return filename
 
    End Function

Thanks for any help