The purpose of this study is to see how the body's immune system changes after replacing and adding new anti-HIV drugs to a patient's current anti-HIV therapy. This study will also see whether adding drugs is safe. Patients who take part in A5136 are also eligible to take part in 2 substudies. The purpose of substudy A5140s is to see how many latently infected cells (cells in which the HIV virus survives) are in the lymph node (small, rounded structures that make disease-fighting cells). Substudy A5155s will be performed to see how many latently infected cells are in the blood before and after replacing and adding anti-HIV drugs.