I'm brand new to the forum so hopefully someone can offer me new information to help my Frostwire as I've done TONS of searching for a solution, none have yet to get it working. :-(
I hope this information that I'm providing below will help (based on what I saw others requesting) and if anything needs clarification or if I've made a mistake, please let me know! Thank you!

(As a side note, my Frostwire program has not had any problems connecting until this afternoon, so I tried to do the update with still no results.)

OS version: Windows Vista
Firewalls: unsure
Ram: 3 GB
Hard Disk Space: 83 GB of 176 GB
Connection type: DSL
Modem & router brand name: ATT 2Wire202
Trying to connect from: Home
Frostwire Version: 4.18.3
Java version: unsure (just updated Java a few minutes ago)
ISP provider: ATT
Is this a your 1st try at FW or is this a new problem with an experienced user? Have used Limewire then Frostwire for many years, just not a very tech savvy person. :-)
12. Do you see a brick wall in front of the blue world icon at the bottom of FW's interface? Yes, always do.

The brick wall suggests you have a firewall issue for a start. See Setting up an exception for LimeWire in your software firewall (click in link) but of course you would add FrostWire, not LimeWire in the exceptions of the Vista firewall.

Check your control panels & see if you have any other firewalls. Usually if using another firewall an icon will show on bottom right of tray.

Also, 2Wire devices often need port forwarding when using p2p sharing applications but let's try the above first.

Ok, I did everything in the alternate forum you linked me to.
I'm still encountering the same problem, but I'm not sure if I'm supposed to.

Do this simple test for us. Using your browser go here: http://www3.limewire.com:6346/ The page should say 'Your test worked!'. What happens when you go there?

There are more fixes to try here: http://www.gnutellaforums.com/connec...t-connect.html
The info refers to LimeWire but is the same for FW If you want to replace the gnutella.net file, the files linked to are fine to use in FW.

Try to find out which firewall(s) you're using. I don't use Vista, but maybe Control Panel will have an option (security, firewall etc) to show you? You can also hover your cursor over icons in your system tray - see whether any of them belong to a firewall.