i'm having the same problem trying to install limewire on my powermac with os 8.6 at home. the same "Unable to launch java application - MRJ may not be installing correctly" message continues to vex me. no problem installing limewire on os 9 at work. in addition, the same message occurred when i tried to launch a different gnutella/java based application called furi. it seems that if both limewire and furi cannot launch java then MRJ may truly not be installed correctly. i've trying installing both MRJ 2.2 and 2.2.5 but neither work. i haven't gotten an answer from anyone at the MRJ forum yet. any ideas here at the limewire end?