C++11 Threads: condition variable leads to an unexpected behaviour

I'm trying to sync two threads using condition_variable in c++11. I'm a using eclipse under ubuntu, and everything is compiled with g++. Both threads are in the same class. The first thread increments a private variable of the class:

void Test::test::Loop()
{
    int loops = 48;
    while (loops > 0)
    {

        std::lock_guard<std::mutex> lock(this->m);
        this->index++;

        // Simulate work
        std::this_thread::sleep_for(std::chrono::milliseconds(10));

        this->Processed = true;
        this->c.notify_one();

        loops--;

    }

    return;
}

As a first test I'd like to display this->index in the other thread:

void Test::test::Process()
{

    while(this->ProcessData)
    {

        std::unique_lock<std::mutex> lock(this->m);

        while(!this->Processed)
            this->c.wait(lock);

        printf("\n%d", this->index);
        fflush(stdout);

        this->Processed = false;

        this->m.unlock();
        this->c.notify_one();

    }

     return;
}

I also tried with this->c.wait(lock, [this] { return this->Processed;}). The result is that the program displays only the number 1, and never stops... What am I doing wrong? This is the fist time I really used condition_variable, but as far as I understood c.notify_one() should allow the second thread to display the variable for each iteration.

Sorry if the question's already been asked, but I didn't really find anything similar. Thanks for your help.