I'm in there now, but yeah, a lot of people having trouble this season. Hope it will get addressed soon. It's iffy for me too, can get in sometimes, can't some other times. Used to not have any issues before the switch.
before you click start, click on the Server and Network hyperlink and make sure it is set for web.seahawks.net and make sure the port is 6667. The channel should already say #Seahawk_Chatters
I can never get into the chat room via the link on this web page. I installed an add-on for Firefox though (Chatzilla) that works every time. You just need the server info that was posted above and you are good to go.
It would be nice if they could fix connecting to the chat server directly from this site though. It's been reported numerous times but hasn't been fixed yet.