The next two suggestions would be 1. to try deleting LW's preferences folder called .limewire (whilst LW is closed!) & found here:
Windows NT 4.0 / 2000 / XP: C:/Documents And Settings/your_username/.limewire
OR Windows 98 / ME: Your .limewire folder is in "C:\My Documents" (BUT make a note of all your LW settings 1st, b/c after you delete the LW prefs folder you'll need to reset them.)

2. Uninstall Java 1.5 & install 1.4.2 instead & see if that makes any difference. Some people have had problems with Java 1.5 & then when they used 1.4.2 things were fine.

How many incomplete & shared files do you have (approx)? How much ram?

A late suggestion would be to try the LW Beta 4.3.4 which is not much different but fixed some people's problems: http://www.limewire.com/english/content/beta.shtml