FB tab application opens in new window, not in iframe [Firefox 6]

My Facebook iframe app acts weird in Firefox 6. When you click bookmark on the left, the app opens in new browser tab inst开发者_如何学运维ead of being displayed in an iframe. In other browsers (IE 7+, Chrome and Firefox 3.6, 4 & 5) everything works pretty fine.

Here's the link: https://www.facebook.com/pages/TestPage/159257547490048

Click the "TESTAPP" link to see it in action. Any ideas for a workaround?

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You're using an http header to redirect to the php sdk generated login url. I ran into the same issue today. Try the following instead...

$user = $facebook->getUser();

if ($user)
{
     // User is logged in
}
else
{
    $login_url = $facebook->getLoginUrl();

    die('<script>window.top.location.href = "' . $login_url . '";</script>');
}

Edit: for reference, I'm using php sdk 3.1.1