This was a bug with LW 4.2 I'd suggest you downld the beta 4.3.3 from here: http://www.limewire.com/english/content/beta.shtml or if you're a pro user you can downld it from the bottom of your personal downld page.

If still have problems then try those fixes again: Fixes for Limewire

Also do a system check. Use your system & 3rd party utilities to check your HDD out & defragment it also.