Royal Mail SmartStamp closed to new business

Royal Mail's SmartStamp service that allows small businesses to print their own postage on label printers is currently closed to new businesses:

I am sorry to say that SmartStamp is not currently available to new customers due to a technical  problem.

There is also no specific timescale for new accounts:

We do not yet know when the service will be available again to new users.

If you try to sign up on their website you get this message:

Service Update

New subscriptions to our SmartStamp service are currently disabled. We are sorry for any inconvenience this may cause. We are working hard to resolve this issue.

Thank you for your patience.

This problem comes after a series of blunders by the Royal Mail, including the SmartStamp service failing for several days over the critical Christmas period causing huge headaches for small traders and ebayers who were unable to print postage.  It was also claimed to have suffered intermittant outages over February and March, and in December many customers were charged twice for their postage.