Memory leak i vb.net kode

VBDotNet kode 

 Me.WebBrowser1.Url = New Uri(current.Url)

VBDotNet kode 

 Imports System
 Imports System.Xml
 Imports Microsoft.Win32
 
 Public Class frmWebRotator
 
     Private urlTimeIndex As Integer
     Private _urlTimes As List(Of UrlTime)
 
     Public Property UrlTimes() As List(Of UrlTime)
         Get
             Return _urlTimes
         End Get
         Set(ByVal value As List(Of UrlTime))
             _urlTimes = value
         End Set
     End Property
 
 
     Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
         With Me
             .MaximizeBox = False
             .MinimizeBox = False
             '.TopMost = True
             .FormBorderStyle = FormBorderStyle.None
             .WindowState = FormWindowState.Maximized
         End With
 
         'Cursor.Hide()
         DisableScreensaver()
 
         Try
             Dim xmld As XmlDocument
             Dim xnodelist As XmlNodeList
 
             xmld = New XmlDocument()
             xmld.Load("c:\WebRotator.xml")
             xnodelist = xmld.SelectNodes("/root/webpage")
 
             Me.UrlTimes = New List(Of UrlTime)
             For Each node As XmlNode In xnodelist
                 Dim urlTime As New UrlTime(node.ChildNodes.Item(0).InnerText, Integer.Parse(node.ChildNodes.Item(1).InnerText))
                 Me.UrlTimes.Add(urlTime)
             Next
 
             'Følgende linjer er til test.
             'Me.UrlTimes.Add(New UrlTime("http://www.google.com", 5000))
             'Me.UrlTimes.Add(New UrlTime("http://www.bing.com", 2000))
             'Me.UrlTimes.Add(New UrlTime("http://eksperten.dk", 8000))
 
             Me.urlTimeIndex = Integer.MaxValue
             Me.Timer1.Interval = 1
             Me.Timer1.Start()
         Catch ex As Exception
             MessageBox.Show(e.ToString)
         End Try
 
 
     End Sub
 
     Private Sub Timer1_Tick(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Timer1.Tick
         Me.Timer1.Stop()
         Me.readyStateLabel.Text = "Loading..."
 
         If Me.urlTimeIndex >= Me.UrlTimes.Count Then
             Me.urlTimeIndex = 0
         End If
 
         Dim current = Me.UrlTimes(Me.urlTimeIndex)
 
         Me.Timer1.Interval = current.Duration
         Me.WebBrowser1.Url = New Uri(current.Url)
 
         Me.urlTimeIndex = Me.urlTimeIndex + 1
     End Sub
 
     Private Sub Form1_KeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.KeyEventArgs) Handles MyBase.KeyDown
         Select Case e.KeyCode
             Case Keys.Escape
                 Me.Close()
         End Select
     End Sub
 
     Private Sub WebBrowser1_PreviewKeyDown(ByVal sender As System.Object, ByVal e As System.Windows.Forms.PreviewKeyDownEventArgs) Handles WebBrowser1.PreviewKeyDown
         Select Case e.KeyCode
             Case Keys.Escape
                 Me.Close()
         End Select
     End Sub
 
     Private Sub DisableScreensaver()
         Dim regKey As RegistryKey
         Dim regVal As String
         regKey = Registry.CurrentUser.OpenSubKey("Control Panel\Desktop", True)
         regVal = regKey.GetValue("ScreenSaveActive")
 
         If regVal = 1 Then
             regKey.SetValue("ScreenSaveActive", "0")
         End If
 
         regKey.Close()
     End Sub
 
     Private Sub frmWebRotator_FormClosing(ByVal sender As System.Object, ByVal e As System.Windows.Forms.FormClosingEventArgs) Handles MyBase.FormClosing
         Dim regKey As RegistryKey
         Dim regVal As String
         regKey = Registry.CurrentUser.OpenSubKey("Control Panel\Desktop", True)
         regVal = regKey.GetValue("ScreenSaveActive")
 
         If regVal = 0 Then
             regKey.SetValue("ScreenSaveActive", "1")
         End If
         regKey.Close()
     End Sub
 
     Private Sub WebBrowser1_DocumentCompleted(ByVal sender As System.Object, ByVal e As System.Windows.Forms.WebBrowserDocumentCompletedEventArgs) Handles WebBrowser1.DocumentCompleted
         Me.Timer1.Start()
         Me.readyStateLabel.Text = "Ready - Luk vinduet på 'Esc'"
     End Sub
 End Class
 
 Public Class UrlTime
 
     Public Sub New(ByVal url As String, ByVal duration As Integer)
         Me.Duration = duration
         Me.Url = url
     End Sub
 
     Private _url As String
     Public Property Url() As String
         Get
             Return _url
         End Get
         Set(ByVal value As String)
             _url = value
         End Set
     End Property
 
 
     Private _duration As Integer
     Public Property Duration() As Integer
         Get
             Return _duration
         End Get
         Set(ByVal value As Integer)
             _duration = value
         End Set
     End Property
 
 
 End Class