PyQt: how to use QWebPage with an anonimous proxy

Question

This is driving me crazy.

I want to show in a QWebPage an url, but i want to do it passing by an anonimous proxy.

Code

#setting up the proxy

proxy = QNetworkProxy()
proxy.setHostName("189.75.98.199") #just examples
proxy.setPort(1111)
proxy.setType = QNetworkProxy.HttpProxy

#setting the manager

manager = QNetworkAccessManager()
manager.setProxy(proxy) #setting the proxy on the manager

#setting the proxy as application proxy

QNetworkProxy.setApplicationProxy(proxy) #seems to do nothing..

#web page

webpage = QWebPage()
webpage.setNetworkAccessManager(manager) #maybe.. but it doesn't work

webpage.mainFrame().load(QUrl("http://www.foo.bar") )

I call a test page which tells me the headers (on a php server, so i look at $_SERVER), and remote_addr is always my ip, not the proxy ip.

What's wrong?

Can you help me? I'm using PyQt 4.8.3.