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 
Have you looked at the sticky at the top of this section? 
http://www.gnutellaforums.com/showth...threadid=51357
If not, please do. If so, what fixes have you tried. Do the port test & see what result you get. 
Do you see the firewall icon (brick wall in front of the blue earth)?
Within LW, go tools > options > bug reports > view example. Scroll down to 'recieved incoming this session'. Is it true or false?