Have a look through this thread
Connection problems? Check here first!

Just double check your firewall settings & make sure they're still as they should be. Do the port test & see what result you get. Did anything change (like new hardware, change of ISP, someone fixing your computer) before you stopped connecting?

What are your details?

OS(Win XP etc)
LW & Java version (help > about LW & you'll see)
Firewall you're using
Modem/router brand & model
ISP
Connection type (DSL etc)
Where you connect from (home, school etc)
Are you sharing a connection with other computers
Is this your first try with LW

*Must be tough living in Pigsnot!!!