threadpool count too much up to 200 threads!

Public Sub DoWork(ByVal objItem As Object)
		static  _sem as Semaphore  = new Semaphore(5,10)    '// Capacity of 10
		Dim objUrl as String = DirectCast(objItem, string)
		Try
			If objUrl Is Nothing Then
				exit sub
			End If
			
			Dim URL as New Uri(objUrl)
			AddItem(URL.AbsoluteUri,gethtml(URL))
		Catch ex As Exception
			debug.Print("Error " & ex.StackTrace )
		End Try
		
	End Sub
	
	Private Sub btnStart_Click(ByVal sender As System.Object, _
		ByVal e As System.EventArgs) Handles btnStart.Click
		btnStart.Enabled =False
		ThreadPool.SetMaxThreads(50, 50)
		System.Threading.Thread.Sleep(1000)
		listView1.Items.Clear
		
		For Each sItem As String In txturls.Lines
			if sItem.Trim <>string.empty
				' Queue a task
				If sItem.Contains("http://")=False Then
					sItem="http://" & sItem
				End If
				
				ThreadPool.QueueUserWorkItem(New WaitCallback(AddressOf DoWork), sItem)
				TotalItems+=1
				tsslTotal.Text =String.Format ("Total Tasks: {0}",TotalItems)
				
			end if
		Next
		
	End Sub