Improved File Browser - no action

HI,

I'm trying to use the ImprovedFileBrowser from the wiki (http://www.unifycommunity.com/wiki/index.php?title=ImprovedFileBrowser). But when the window pops up, I see the current dir but can't select or choose any files/directories :/? The GUISkin "List Item" is pretty default. Maybe my implementation is wrong??

thanks

 void OnGUI()
 {
     if (GUI.Button (new Rect (20,130,180,20), "Button"))
 
     {
 
         m_fileBrowser = new FileBrowser(new Rect(200, 100, 600, 500), "filebrowser", FileSelectedCallback);
 
         m_fileBrowser.SelectionPattern = "*.xml";
 
         m_fileBrowser.DirectoryImage = m_directoryImage;
 
         m_fileBrowser.FileImage = m_fileImage;
 
     }
 
     if(m_fileBrowser != null)
 
     {
 
         GUI.skin = CustomGUISkin;
 
         m_fileBrowser.OnGUI();
 
         GUI.skin = null;
 
     }
 }
 
 private void FileSelectedCallback(string path)
 
 {
 
     m_fileBrowser = null;
 
     m_textPath = path;
 
 }