Usually when this occurs it iis the preference folder issue. If you have a router there could be a problem there. The link below Will take you to the preference folder fix. If that doesn't work a little more Information would be helpful.
http://www.gnutellaforums.com/showth...threadid=36420
OS, Windows 98/2000/XP
CPU, P4 3.0 GHz/AMD 64 3200+Ghz
Memory, 256MB/512MB
Video card & platform Radion 9800/Nvidia 6600/ On board intell 580
Connection, Dial-up/DSL
LimeWire Version 4.8.1/4.9.11
Java Version 1.4.2/1.5.4
Are you using a router, Brand/Model#
What firewall you use if any
What Antivirus if any
Are you new to LimeWire or Experienced
An accurate description of your problem