After some initial testing and an attempt or two at setting up the mibbit client I've concluded that it's going to take more time than I have available to find out what the problem is exactly and how to fix. No matter what I've tried so far with Mibbit it still times out for me.
What did work for me with Mibbit reliably though was using their site directly. Simply went to
their chat site and filled in the necessary details (being sure to click the "Server" link and setting it to "irc.layonara.com") and was logged in to #nwn just fine. See the attached image to this reply. Nothing particularly special.
I've gone and replaced the link on the main irc.layonara.com page with a link to the
Mibbit chat site but the
old mibbit.html page remains available.
As for the port blocking. Being that most malware these days hinges upon remote command interfaces, like using a public irc chat service to issue commands, Anti-Virus and network shaping services can be a problem. Sometimes this is on the ISP level (port 6667 outbound and sometimes 6668 inbound) which is fairly rare or more commonly found on the user's machine itself via firewalls (usually from anti-virus products) and other such "protective" software.
There really isn't much one can do about ISP level blocking short of using a proxy service, which is essentially what mibbit is doing, but traditional proxy services work too. It's probably best to contact the ISP involved and see what can be done.
For client problems like firewalls and anti-virus software, you'll have to refer to your software's particulars on how to "whitelist" (or "unblock" or whatever) port 6667 appropriately.
If for whatever reason you can't connect via the stand-alone clients (like X-Chat or mIRC), the
custom Layonara web-based client, or via the
mibbit site directly... I'm not sure what else I can do to help.
I hope all that answered everyone's questions or at least helped to some degree.
