Cleaning facebook url cache from php - php

Question

I have an issue with the facebook linter feature. I'm trying to clean the Facebook cache of one my URL, with a PHP curl query. As you can see here (Updating Objects), Facebook got an api for scrapping all the content of an URL and update URL Facebook meta. It's the same API used in the Facebook Debugger Tool.
If I use their debugger manually, there is no problem. My URL is correctly scrapped and all corrects meta are retrieved. But it's not the case with a php curl query.
Here my actual code :
$furl = 'https://graph.facebook.com';
$ch = curl_init();
curl_setopt( $ch, CURLOPT_URL, $furl );
curl_setopt( $ch, CURLOPT_RETURNTRANSFER, true );
curl_setopt( $ch, CURLOPT_POST, true );
$params = array(
'id' => "http://www.gametrader-app.com/aTPVev",
'scrape' => true,
);
$data = http_build_query( $params );
curl_setopt( $ch, CURLOPT_POSTFIELDS, $data );
curl_setopt( $ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt( $ch, CURLOPT_FOLLOWLOCATION, 1);
$resultLinter = curl_exec( $ch );
The API result displays incorrect/old facebook meta.
Moreover, I have tried to call directly the URL of the Debugger without success
curl_setopt( $ch , CURLOPT_URL, "http://developers.facebook.com/tools/debug/og/object?q=http://www.example.com");
curl_setopt( $ch , CURLOPT_HEADER , 0 );
curl_setopt( $ch , CURLOPT_RETURNTRANSFER , true );
curl_setopt( $ch , CURLOPT_USERAGENT , $useragent );
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
$str_response = curl_exec( $ch );
I need to do this for one reason. Here the full process :
Publish a new ad on the iPhone App "GameTrader"
Post an open graph on facebook for this publish
That's all ;)
If I don't clean the URL cache on Facebook side before the post open graph, I get this error :
Error during open graph : OAuthException: (#3502) Object at URL
http://www.gametrader-app.com/aTPVev has og:type of 'website'. The property 'ad' requires an object of og:type 'gametrader-app:ad'
Can you help to understand what I'm doing wrong ?
Cheers!