title: Dropbox throws "Invalid redirect_uri" error, although exactly the same url is specified in the app
body: <p>I want to start my Dropbox-app by linking to a dropbox account as specified here: 
  <a href="https://www.dropbox.com/developers/datastore/tutorial/js" rel="nofollow">https://www.dropbox.com/developers/datastore/tutorial/js</a></p>
  
  <p>However, dropbox won't redirect back to my website and throws "Invalid redirect_uri"
  I specified various redirect urls and double checked my app_key, but i could not get it to work. What am i doing wrong?</p>
  
  <p>Thanks in advance!</p>