I downloaded the newest version of Limewire, but the tracks that I had downloaded on the old version did not transfer over. I can I remedy this?

You will need to determine your Saving folder and designate your Shared folder.

First go to Tools>Options>Saving
Take note of your Save Directory & folder.

Now go to Tools>Options>Sharing
Hit "Add" then "Select" your Save Directory & folder

You should now see your Shared folder in addition to the Incomplete folder in the Library Tab.

Hope this helps.