It's hard to tell where the problem lies but.. if I was in your shoes:
I would update both my browser and quicktime and then try again.
Alternatively I would try another browser. Since it might be a bugg or problem that only occurs with the latest browser or quicktime version.
If you are using Internet Explorer as browser, you might want to give Firefox a try.
www.firefox.com
The key is to try as many different ways as possible.
If the problem still remains or get solved by this, please write it here.
Good luck!