I'm curious why you posted a mac question in the Windows section. lol
Some ideas:
Tip: Purge the Downloads Queue!
After opening LW wait 10 to 20 mins or longer before using. Let it settle down 1st.
Also don't use the Resume button on all incomplete files. This can have side-fx such as affect LW's connection quality. This will also stress LW & your comp. If you use Resume/Find sources then just apply it to a couple or so at one time.
You could also try deleting LW's preferences called
.limewire whilst LW is closed & found in the system preferences folder. View preferences folder in list mode & view it by name & .limewire should be at the top of the list. Or else you can use the Find function (apple & F keys.)
What do you mean you paid for it again? If you're a pro user then you just downld it from your personal downld page. Unless your 6 months of free updates had completed.