|I can't register a new account.|
If you find the shop is giving an error or not allowing you to register a new account the chances are that you have already registered an account or the username you have chosen has been taken already.
We're aware of an issue that means the registration process doesn't inform you of this and just gives and error or goes round in circles. At the present time we haven't found a solution.
In the first instance please try using the account recovery options in the login pane at the side of the shop pages.