[jQuery] :not selector

when I do this:
$("*:not(.oneClass,(.oneClass :nth-child(n)))")
or
$("*:not(.oneClass,.oneClass :nth-child(n))")
it returns 0 elements, but
$(".oneClass,(.oneClass :nth-child(n))")
returns only about half of the elements i get with
$("*")
am i doing something wrong?
is there any known bug's of the :not selector for this sort of things?