In March 2004, participants in this study were unblinded. Participants on DAPD placebo were given the option of discontinuing the placebo and replacing it with an active antiretroviral, if one is available. Participants on active DAPD were given the option of continuing DAPD through Week 48, or discontinuing it and replacing it with another antiretroviral agent. All participants may continue to receive ENF through Week 48.