Makes me wonder from where you downloaded the PRO version, since you say you switched to the new basic version. If I remember correctly, LW 4.12.3 was released some time around June 2006 (4.12.3 (06.20.2006)), which means that you should still have been in the 6 month update time limit.
If you didn't get it from the official LW website [
http://www.limewire.com/], then you might have gotten some worm/trojan or virus with a warez version of LW.
Just a thought though.
Another possibility would be that using the online update installer might have installed it incorrectly. You could try to download the offline installer of your PRO version (assuming that you bought it from the LW website) using your personal download page you should have gotten by email when purchasing the PRO.
In any case, do not use the Add/Remove Programs function of the Control Panel. Always use Start>Programs>Limewire>Uninstall to remove it.
