Hello
Anyone can help me with this problem?

Code:
Imports Microsoft.VisualBasic

Imports System
Imports System.Web
Imports BlogEngine.Core.Web.Controls
Imports BlogEngine.Core
Imports System.Net.Mail
Imports System.Threading

<Extension("Pings all the ping services specified on the PingServices admin page and send track- and pingbacks", "1.3", "Blog")> _
Public Class SendPings
    Shared Sub New()
        AddHandler Post.Saved, AddressOf Post_Saved
        AddHandler Page.Saved, AddressOf Post_Saved
    End Sub

    Private Shared Sub Post_Saved(ByVal sender As Object, ByVal e As SavedEventArgs)
        If e.Action = SaveAction.None OrElse e.Action = SaveAction.Delete Then
            Exit Sub
        End If

        Dim item As IPublishable = DirectCast(sender, IPublishable)
        If item.IsVisibleToPublic Then
            Dim url As Uri = item.AbsoluteLink
               ThreadPool.QueueUserWorkItem(AddressOf Ping, item)
        End If
      
    End Sub

    Private Shared Sub Ping(ByVal item As IPublishable, ByVal itemUrl As Uri)
        Try
            System.Threading.Thread.Sleep(2000)

            ' Ping the specified ping services.
            BlogEngine.Core.Ping.PingService.Send(itemUrl)

            ' Send trackbacks and pingbacks.
            If Not BlogSettings.Instance.EnableTrackBackSend AndAlso Not BlogSettings.Instance.EnablePingBackSend Then
                Exit Sub
            End If

            If item.Content.ToUpperInvariant().Contains("""HTTP") Then
                BlogEngine.Core.Ping.Manager.Send(item, itemUrl)
            End If
        Catch generatedExceptionName As Exception
            ' We need to catch this exception so the application doesn't get killed.
        End Try
    End Sub

End Class
the problem is this
Method 'Private Shared Sub Ping(item As BlogEngine.Core.IPublishable, itemUrl As System.Uri)' does not have a signature compatible with delegate 'Delegate Sub WaitCallback(state As Object)'.

please help me