If QNetworkAccessManager succeed doing a request, the next one that fails don't fire the finished() signal.

Here is some test code:

void foo::finished(QNetworkReply* r)
{
printf("finished %s %d\n", qPrintable(r->url().toString()), r->error());
r->manager()->get(QNetworkRequest(QUrl("http://google.com")));
r->deleteLater();
}

foo::foo(QObject* parent) : QObject(parent)
{
QNetworkAccessManager* m = new QNetworkAccessManager(this);
connect(m, SIGNAL(finished(QNetworkReply*)), this, SLOT(finished(QNetworkReply*)));
m->get(QNetworkRequest(QUrl("http://google.com")));
}

Run this, and after it starts reporting success unplug the network.