SQL 2012 :: SSIS Script Task Hangs When Trying To Download Missing File From A URL?

I have an SSIS package that inserts website URLs from a SQLServer table into a variable used by an HTTP Connection Manager, then downloads the data files from those URLs using a ForEach Loop and a Script Task. Works beautifully when a data file is found at the URL, but hangs if no data file is found. I've set the Timeout property on the HTTP Connection Manager to 30 seconds, but doesn't work. how to first check if a data file exists, of if the request returns nothing, or how to trap this situation in a try-catch?

Here is the VB code I'm using in the Script Task:

Public Sub Main()
Try
' Connect to website using HTTP connection manager
Dim nativeObject As Object = Dts.Connections("HTTP Connection Manager").AcquireConnection(Nothing)
' Create a new HTTP client connection
Dim connection As New HttpClientConnection(nativeObject)

[code].....