oops, I figured it out.

When you load up an older version of limewire, it asks you if you want to update. If you click "yes" it quits limewire and opens a browser to the download page on www.limewire.com. I had thought that this was the same download page as a complete download, however when you download from this page, into the same folder in which the previous "limewire" folder is, it does an update -- it circumvents autosetup and keeps libraries and preferences.

I think this is the intended method.

Thanks for the reply