Athiests have a hard and soft school of thought. Hard means there is no god and soft means it is unknown. Soft is really agnostic but many atheists balk at being called agnostics so they play a sort of game with the term atheism.
At least this is my take on the affair. If there is so subtle nuance I'm missing I'm more than open to hearing about it.
Atheism traditionally meant without a god not without a belief in god. Later schools of thought modified it to the later. According to the limited reading I've done on the subject anyway. Studying this leaves me a bit cold so I give the problem its appropriate measure of time.
John Thornton