i have had similar probs in the past and can offer this advice

make sure you do not have 2 or 3 shared folders(can happen after up******* re-installation , as this can cause confusion nb they may not be in your system folder, try your documents folder

toss your limewire prefs, your shared folder(minus files) and your incomplete folder(minus any downloads you wish to keep)
empty the trash ,do a restart then start up limewire it will create new folders in your preferences folder
you will have to reconfigure limewire but that isn't a lot

finally shut limewire down and put any files shared or incomplete files in their respective folders

hope this helps