title: php - php Thumb file not writeable
body: <p>i'm using ffmpeg for extracting a video frame from which i want to create a thumbnail using php thumb.
  creating the video frame works, but when trying to save the thumbnail file (under a different name - same directory) i'm getting this error:</p>
  
  <pre><code>PHP Fatal error:  Uncaught exception 'RuntimeException' with message 'File is not writeable, and could not correct permissions: d:/Webs/bla.jpg' in D:\Webs\phpThumb\lib\GdThumb.inc.php:656
  </code></pre>
  
  <p>it can't be a permission problem as i can already store the videoframe into the same folder.</p>
  
  <p>any ideas what could be wrong?</p>