Hello, my adsense account is a bit old, and I don't quite remember the steps I've taken to register. But the problem on your registration looks like something related to the domain you're trying to register. Somewhere on the registration you've putted a domain name, that probably isn't yours. Probably you've putted hubpages.com...
The domain name is a required field? If not, don't put anything there, if it is, then you got a problem, but you can try the following:
- Go to blogger.com and register for an account. If you already have a google account, gmail for example, just use the login info from that account.
- Then create a blog, even if you leave it empty and delete it later, and on the blog setup you should have the possibilitie of setting up adsense, either adding an already existing publisher id, or creating a new one.
- Select create a new one, and then you'll probably just need to fill out a few fields, and you're done.
After you've created your account, google will send you a letter home (so be sure to put the right address) with a pin number that you'll have to insert on the adsense page. The account will be activated imediatelly, but you'll only be able to receive payments after inserting the pin number.
Hope it helps.