Nice prinukun!
I have no idea what I am doing wrong actually. How did you do it?
simply !! try to add by manual "https://" instead of "http://"
for your dropbox hosted file, you will notice dropbox already support the security service for your files <img src="smileys/smiley2.gif" border="0" align="middle" /> , so you can host your game on dropbox and benefit from security service for your FB apps <img src="smileys/smiley36.gif" border="0" align="middle" />