VB Web request not repeating after failure, try/catch not working

I am trying to send a web request to a Snom PA1 bell. The bell rings periodically throughout the day, but occasionally times out trying to contact the bell. That would be fine, but after this happens a couple times, the web request stops sending alltogether. the sub still runs, but no bells. Also, while debugging, the webrequest throws a webexception that is not handled by the catch, even though it is contained within the try/catch.

Does anyone know why the web request would stop working after a failure?

Private Sub ringIPBell(ByVal params() As Object, Optional ByVal secondattempt As Boolean = False)

        Dim IPaddress As String = params(0)
        Dim ringSeconds As Double = params(1)
        Dim wr As Net.HttpWebRequest

        If ringSeconds = 2 Then
            wr = Net.HttpWebRequest.Create("http://" & IPaddress & "/line_login.htm?l=2")
        Else
            wr = Net.HttpWebRequest.Create("http://" & IPaddress & "/line_login.htm?l=1")
        End If
        wr.Method = "post"
        wr.CachePolicy = New System.Net.Cache.RequestCachePolicy(System.Net.Cache.RequestCacheLevel.NoCacheNoStore) 'added Oct2010
        wr.Credentials = New Net.NetworkCredential("correctName", "correctPassword")

        Dim postdata As String = "PLAY_RINGER:1=Play Ringer"

        wr.ContentLength = postdata.Length + 2
        Dim requestStream As IO.Stream, strmwrit As IO.StreamWriter
        Try

            requestStream = wr.GetRequestStream()
            strmwrit = New IO.StreamWriter(requestStream)
            strmwrit.WriteLine(postdata)
            strmwrit.Close()
            Dim responsestream As New IO.StreamReader(wr.GetResponse.GetResponseStream)


            Catch ex As System.Net.WebException
            If Not secondattempt Then
                ringIPBell(params, True)
            End If
            Dim testvar As String = ex.ToString
        Catch ex As Exception
            Beep()
        End Try

Also, I previously had the following code ringing the bell, but it would only work for one of the two bells, Even though as far as i can tell their settings were identical.

requestStream = wr.GetRequestStream()
            strmwrit = New IO.StreamWriter(requestStream)
            strmwrit.WriteLine(postdata)
            strmwrit.Close()
            requestStream.Close()