A Study of Two Different Doses of ABT-378/Ritonavir in HIV-Infected Patients Who Have Taken Protease Inhibitors and Non-Nucleoside Reverse Transcriptase Inhibitors

Inclusion: * HIV positive * Are at least 18 years old * Subject has not been treated for an active AIDS-defining opportunistic infection within 15 days of screening * HIV RNA level \> 1000 copies/mL * Previous therapy with at least one protease inhibitor, at least one non-nucleoside reverse transcriptase inhibitor and at least one nucleoside reverse transcriptase inhibitor Exclusion: * Subject is pregnant or breast-feeding * Subject has received an investigational drug within 30 days prior to screening * Have a history of pancreatitis * History of intolerance to ritonavir * Abnormal laboratory tests at screening