Reading spreadsheets using Google Spreadsheets API

I’m trying to read a spreadsheet feed using the Google Spreadsheet API. For that, I’m using a HTTP Service with an URL Loader.

I actually don’t have any problems for making it work in my flex environnement, but once I publish it : I have the security sandbox problem.

After searching in the Internet, it seems related to the crossdomain.xml file, so I added :

Security.loadPolicyFile("http://spreadsheets.google.com/crossdomain.xml");

to my AS file. But it still don’t work.

I also stumbled upon this :
http://en.flash-ripper.com/2008/vote-for-crossdomainxml-for-google-apis-and-services/
And I was confused as I can see a crossdomain.xml file over spreadsheets.google.com, but it just don’t work.

I would appreciate any help, some people told me to use JSON in place.

Thanks,