I have a 233 mhz. iMac with 160 mb. ram OS 9.2.2 / 10.1.2 partitioned hard drive and I have been using Limewire v.1.8 for months with-out a problem and to-day I downloaded v.2.1 and it works just fine, so therefore I must conclude that you are doing something wrong. All I can sugest is you try again and follow the instalation instructions as they are presented to you.