I've always considered that position agnostic, rather than atheist. Isn't atheism a positive belief that God does not exist?
I've always considered that position (God positively doesn't exist) to be silly, as you can't prove a negative.
I dare you to prove that. ;-)
Actually, though, you can prove a negative, at least in some cases. I once took a rather painful Abstract Linear Algebra class that ended up proving that there was nothing after an "octonion," (or was it nothing after a 16-space transformation? -- I forget now...)