title: $MyInvocation.MyCommand.Path is $null in PowerGUI script editor
body: <p>When trying to debug my powershell script in the powerGUI script editor (2.0.0.1082) the  $MyInvocation.MyCommand.Path is $null. 
  It works when running the script via powershell. 
  Running it in Powershell_ise.exe (on one of our servers) also works fine.</p>
  
  <p>Have anyone else had the same problem or know what's wrong?</p>
  
  <p>Here's my powershell version:</p>
  
  <pre>
  Name                           Value
  ----                           -----
  CLRVersion                     2.0.50727.4927
  BuildVersion                   6.1.7600.16385
  PSVersion                      2.0
  WSManStackVersion              2.0
  PSCompatibleVersions           {1.0, 2.0}
  SerializationVersion           1.1.0.1
  PSRemotingProtocolVersion      2.1
  </pre>
  
  <p>Server version:</p>
  
  <pre>
  Name                           Value
  ----                           -----
  CLRVersion                     2.0.50727.3082
  BuildVersion                   6.0.6002.18111
  PSVersion                      2.0
  WSManStackVersion              2.0
  PSCompatibleVersions           {1.0, 2.0}
  SerializationVersion           1.1.0.1
  PSRemotingProtocolVersion      2.1
  </pre>