Two answers to your post:

i) Here is a recent analysis of existing evidence: http://hivskeptic.wordpress.com/2008/01/15/hiv-has-never-bee....

ii) A prize of $100.000 "was officially offered to anybody who would demonstrate HIV particles in the blood of allegedly high viral load patients". It has not been claimed yet.

So far, there is ground for a reasonable scientific doubt regarding claiming that HIV causes AIDS. The accumulated evidence is not conclusive unfortunately.