title: Powershell instance locks up main thread
body: <p>I have a Powershell script with a Windows Forms UI from which I create a new Powershell instance, which in turn starts IE (hidden) and grabs information from a website. </p>
  
  <p>Sometimes the UI locks up and only becomes responsive again after manually killing the hidden IE-process via task manager.
  Seemingly IE freezes and this locks up the UI.</p>
  
  <p>Mainly I am trying to understand why this happens. Although it happens every day, so far I was not able to reproduce it by i.e. intentionally creating a new thread which does not respond. 
  Also I thought a new instance can never lock the main thread anyway, or am I wrong and it is to be expected?</p>
  
  <pre><code>$script:Posh1 = [PowerShell]::Create()
  $script:Posh1.AddScript($IEcode)
  $script:Posh1.AddParameter("url1",$url1)
  $script:Posh1.AddParameter("url2",$url2)
  $script:Posh1.BeginInvoke()
  </code></pre>