Can you give us a total desciption of your set up:
1. OS version,
2. What firewalls you have,
3. ram, 4. HDD space available,
5. Connection type,
6. Modem & router brand name & model numbers,
7. Where are you trying to connect from (home, school, work, etc.)?

Try deleting your LW preferences folder. See: Fixes for Limewire