Using Vista shoudn't make any difference. I've just bought a new Toshiba laptop and installed LimeWire 4.16.6 and have had no problems at all. The windows Firewall was turned off by default due to the trial version of Norton Internet security which has it's own Firewall. And you should never have two Firewalls running at the same time.
I would suggest you read as many of the "Sticky" posts at the beginning of this forum and hopefully you will find an answer to your problems.