Br0, try entering a false ID in the registration.
I know it checks to make sure that the blockland id you entered is using the name you entered on the ip you are browsing the site with.
If you're ip changes because it is a dynamically allocated internet protocol address, then when return to blockland attempts to authenticate you when you register to return to blockland, then the ip you're playing on as well as the ip you're browsing the website on will be the same, just different than before, so it will still work.