Have you tried updating your Java? I know it shouldn't make any diff because the basic version runs fine, you could try it if you like
http://www.java.com/en/download/manual.jsp
To be honest I'm not sure what could be causing your problems but other people here might have more clues, wait & see if anyone else responds to your thread. I know it's frustrating for you but be patient & hopefully one of the gurus will have some ideas!
Did you have the preferences for Pro set up exactly the same as basic?
Try deleting the preferences folder, see points 2 & 3 here
Fixes for LimeWire