Aweber授权代码不起作用

这里有一个奇怪的问题：当我授权我的Aweber应用程序时，授权码第一次就工作了。

但是，当我刷新页面时，会出现一个错误：AWeberAPI异常：

Type: UnauthorizedError 
Msg : RequestToken key is invalid.     https://labs.aweber.com/docs/troubleshooting#unauthorized 

文档：https://labs.aweber.com/docs/troubleshooting#unauthorized

请帮帮我，这真的很令人沮丧。这是我正在使用的代码：

require_once('aweber_api/aweber_api.php');
try {
# set $authorization_code to the code that is given to you from
# https://auth.aweber.com/1.0/oauth/authorize_app/YOUR_APP_ID
    $authorization_code="Azh...";
$auth = AWeberAPI::getDataFromAweberID($authorization_code);
list($consumerKey, $consumerSecret, $accessKey, $accessSecret) = $auth;
# Store the Consumer key/secret, as well as the AccessToken key/secret
# in your app, these are the credentials you need to access the API.
//$account = $aweber->getAccount($accessKey, $accessSecret);
}
catch(AWeberAPIException $exc) {
print "<h3>AWeberAPIException:</h3>";
print " <li> Type: $exc->type              <br>";
print " <li> Msg : $exc->message           <br>";
print " <li> Docs: $exc->documentation_url <br>";
print "<hr>";
}