HD quality in JW Player doesn't work

Steps to reproduce:

1. Create a new page as a simple user or admin
2. Edit the page in wiki mode and add a JW code, using an external youtube link:

   {{jwplayer attachment="http://www.youtube.com/watch?v=1o9efYEmXKA" /}}

3. Save the changes
4. Click Play
5. Click Pause
6. Click on HD and try in pause mode all the quality options

Expected results: The quality options must be applied. You should see the differences of quality between them.

Actual results: No difference between the options.