If you find that you are unable to view your site and receive a message saying your IP address is blocked. You can always unblock your IP address from the client area. When you first login on the left most menu you will see a button on the left under shortcuts called Unban Centre.
Once you click on this link it will show you any compatible services and will show a lock icon to the right. Clicking on the lock will display a popup allowing you to verify your IP or a users IP to see if it's blocked, if it is blocked it will let you unblock it.