Hi dan.
You should have the latest version of stuffit installed anyway, but you could get around installler problems (if you are using OS 10.2), by trying http://baghira.han.de/~jum/LimeWire.html

It's the latest (includes all recent developments--like a beta) build of LimeWire Pro for OSX that Jens-Uwe Mager has generously made available. It doesn't use an installer--just the good old drag-to-harddrive method.