This dreaded error hit my system recently. Xbox on line support did not shed any light, while a quick google on this code revealed that this problem had become quite common recently. Users complained that Xbox phone support was not effective. Here is the fix. The error indicates that you xbox live purchasing functions have been "locked". To unlock ensure that your personal details, name, address, etc precisely match your credit card deteils in terms of both content and capitalisation. Call xbox phone support and advise you have made this change and ask them to kick the problem to the credit department. Wait 24-48hours and miracle your account works. Happy "xbox live-ing".

Hope this has been useful to you!! I haven't as yet tried it so don't blame me if it doesn't work :)