title: Set-MailboxFolderPermission does not, what it should do
body: <p>I'm currently working on a script to change some Mailboxfolderpermissions in Exchange 2010. 
  The basic functions work, I can read out the current permission-status and I can set permissions, but the cmdlet Set-Mailboxfolderpermission does not correctly set the permissions.</p>
  
  <p>For example:</p>
  
  <pre><code>Set-MailboxFolderPermission -Identity Owner:\Calendar -User TargetUser -AccessRights Contributor
  </code></pre>
  
  <p>This results in a custom named setting, where nothing changed in relation to the previous setting.
  Same thing when I substitute <code>Contributor</code> with the explicit permissions <code>FolderVisible, CreateItems</code>.</p>
  
  <p><strong>Update:</strong></p>
  
  <p>I just tried to use the cmdlet from the shell and there it works.
  To test whether the internal output is right, I printed the permissions on the shell and everything was fine. 
  Right now I'm wondering even more.</p>
  
  <p>What is the point here? Is it a bug, am I to frustrated to see the right way out of my problem?</p>