Randomized treatment will continue during an average of approximately 2 years, and will be followed by a period of 12 weeks' continuous treatment, for patients in both arms. Endpoints: The amount of drugs used, side effects, viremia and CD4 counts, number of clinical events, at the end of the randomized treatment period, and again 12 weeks later. STACCATO: A Randomized Trial of CD4 guided Treatment Interruption, Compared to Continuous Treatment, for HIV Infection