Sounds like you have multiple problems.
Can you give us a total desciption of your set up:
1. OS version? (eg: Windows 98)
2. What firewalls you have?
3. ram?
4. HDD space available?
5. Connection type? (eg: dialup, broadband, cable, etc.)
6. Modem & router brand name & model numbers?
7. Where are you trying to connect from (home, school, work, etc.)?
8. What version of Limewire (LW) & Java do you have? (Go to LW's menu Help>About LW...)
9. Who is your ISP provider?
So you can't reach
http://www3.limewire.com:6346/ with your browser. It is very important that you give us as much info so we can find what the issue is & try to sort this out.