LOL that source states that only 2% of them consider themselves atheist. Nice try though.
No one calls themselves a strong A atheist, it's not the 70s. These Jews who call themselves secular don't believe in a god but keep Jewish practices. Calling yourself atheist is seen as discarding that. I know Jews who wear kippah, do all the stuff during High Holy Days etc but don't actually believe in their ancient sandmyths about some guy who created everything.
The fact that most Jews don't believe in a god today is actually one of the biggest subjects for orthodox rebbs. A couple such holy men waxing poetic about this "problem": http://www.ynetnews.com/articles/0,7340,L-3809043,00.html