Update your Java. Use the JRE offline installer & remove your current Java version before you install the new one.
http://java.sun.com/javase/downloads/index_jdk5.jsp

If things are freezing only when you're using (I guess you mean downloading) LW try these:
In LW tools > options > speed. Disable ultrapeer capabilities.
Reduce your upload & download bandwidth a bit.
Don't download too many files at once, just 1 or 2...same for resuming incomplete files.
Disable iTunes sharing.

I'm having the same problem. I've tried all of the suggestions posted and I'm still having the problem!

I've used Limewire without any problems before. But when I, a couple of days ago, opened it my computer freezed, and have done that every time I try to open it. I uninstalled it, but now when I'm going to install it again, it just works until I'm gonna open Limewire, then the computer freezes again and I have to restart it. And the installation never compleates... any (good) suggestions? PLEASE!