How long ago did you buy Pro? You do know that you only get free upgrades for 6 months? How many email addresses have you had in 6 months?
Go to the support page & try all the email addresses you've had
http://sales.limewire.com/support/pro_lookup.php

Providing you bought from www.limewire.com less than 6 months ago, there are some links here
http://www.gnutellaforums.com/showth...500#post190500