Just a heads up Kevin, the windows situation (yeah, I know you love this. :-))
with having piklist parts inside the theme folder doesn’t work with the latest version of piklist.

So I found a solution.

Apparently in the themes path check in class-piklist.php around lines 200 or so.
The self::$paths[$_theme] produces the full theme path but adds in the folder /piklist to the end, while the $_part variable also adds /piklist to the beginning of all parts, making sure nothing loads from the themes piklist folder.

I removed the themes additional piklist folder from its path, and voila. Works.
I changed the following:

        foreach (array('theme', 'parent-theme') as $_theme)
        {
          $spt = self::$paths[$_theme];
          $spt = substr($spt,0,strlen($spt)-8); // EDITED BY MARCUS
          if (isset($spt))
          {
            if (file_exists($spt . $_part))
            {
              $_file = $spt . $_part;
              break;
            }
          }
        }
        // d($_file);
        if (file_exists($_file))
        {
          break;
        }

Marcus