Can't connect anylonger - it shows "limewire is connecting"....I have windows XP professional (version 5.1), Java version 1.6.0_18, conected through cable; HD with 23GB available. I've checked the windows firewell and limewire is mark as exception. Any other tips?

hi jcg Firstly check If LW 5 Will Not Connect

If still problems post back the other details you haven't supplied yet to help us more System details - help us to help you (click on blue link)

I basically followed all steps you have indicated - it seems that after reinstalling the Java, I've got a connection back.
However going to Advance tools > connections > it sill says that " you are behind a firewall and support firewall transfer.
I've checked windonws firewall and limewire is marked as exception
Do I have to do something else?

Good to hear.
After you reboot your computer next time, see if it has same problem.
Make sure only one firewall is active.
If still the firewall issue, please supply details of modem/router brand name & model number as this might be the issue.