face book application and google application

[eluser]searain[/eluser]
I found this thread.

http://www.simpleprojectz.com/2008/10/fa...deigniter/

Instead set up

$config['uri_protocol'] = “PATH_INFO”;

like this thread said, I need to set

$config['uri_protocol'] = "ORIG_PATH_INFO";

It works fine now.

But I am so sure what is the logic here.

In simple words

$config['uri_protocol'] = "ORIG_PATH_INFO";

to make the fb iframe work, why?