Downloading Folder From Amazon cloud giving an error: (403) Forbidden

Hi all,

I am Downloading folder from amazon cloud using my app if my Folder contains only files then its it is downloading perfectly but when my Folder contains sub folder in it then it is giving me  an error:

{"Access Denied"}

"{"The remote server returned an error: (403) Forbidden."}"

im not getting why this is happening.

thanks.