If one follows Brucie's link one can read:

Five percent of AIDS patients tested for HIV do not demonstrate the presence of antibody or virus and only about 50 % of all AIDS patients in the United States have ever been tested for HIV antibody

It's a long way from that statement to Brucie's statement cited above.

I cannot say anything about the physiology in that article from lack of knowledge, but I know about the logic of tests. While he makes a good case for HIV being not sufficient to cause AIDS (I don't know anybody claiming that, by the way, that's uncontroversial as far as I see), I find his logic regarding the relevant question of HIV being a necessary condition or not very weak. But it is good reading for finding out about the difference between the two ways (necessary, sufficient) we can talk about causation. Only one of them is relevant for the discussion.

And: the article is from 1990!

Wolfgang