The purpose of this study is to determine the antiviral activity, safety and tolerability of 14 days of different doses of TMC114 to treat HIV-1 positive patients whose condition is failing on a current treatment regimen that includes a protease inhibitor (PI) (a medication used to reduce the amount of HIV virus in the blood).To be considered for the study, patients must have a documented resistance to at least 2 of the current PIs. Pharmacokinetics and pharmacodynamics of TMC114 will also be assessed.