This is where I think the problem is...initially two invitations were sent out to everyone.
One invitation was sent for the SWOAPE Announce Group which is basically an online e-mail resource for the club. If people didn't already have a Google account, they could then sign up for one and that created some confusion, at least it did on my part.
A second invitation was sent to Join the new website at http://swoape.wikidot.com/
This is the site you sign up with your e-mail address and then create an account (register). The create an account versus register also created some confusion on my part, but then again, I am easily confused
In your case, you accepted the invite to the SWOAPE Announce group (you already had a Google account) but have not yet accepted the invitation to the website. You still need to go to the site and sign up with your e-mail address and create your account.
Looking back, I think we should have sent the invitations to the website first then once people were signed up at the site, sent out invitations to the SWOAPE Announce group on Google. This is my fault as I was probably overly excited about finally getting a website up for the club I probably rushed things too much...hindsight is 20/20 isn't it?