Are you running as administrator? See this thread for more info.
http://www.gnutellaforums.com/genera...tml#post285065

Right click on the LW icon on your desktop > properties > compatibility (that's for XP, hope it's the same for Vista!) & run in compatibility mode for XP.

If you're still having problems try deleting LW's preferences folder when LW's properly closed. See point 3 here.
Fixes for LimeWire
This will kill all of your settings within options, you'll have to go back through afterwards & reset things. If you're not sure of your settings, go through LW's tools > options & write them all down, so that you can reset things later.
http://www.gnutellaforums.com/genera...der-vista.html

In LW click on file > disconnect. Wait 5 mins then file > connect.