You raise a good point that I hadn't really thought of before. But thinking about it, it's still not very clear. Perhaps because of your use and demonstration of 'personal position' when I asked for 'belief'.
Also, atheism is the rejection of the proposition of a god, and in a wider definition, of a religion. Now just because I choose to reject that proposition, and hold another proposition to be true or valid, does not make the act of rejection of the original proposition a religion in and of itself.
Rejection of a religion is not a religion in and of itself. Just like the rejection of a scientific hypothesis is not a hypothesis in and of itself.