HDCP Error on Windows 8 running 4OD

I've just tried playing a video through the 4OD metro app and I get this error:

ERROR_GRAPHICS_OPM_OUTPUT_DOES_NOT_SUPPORT_HDCP = 0Xc0262513

My setup is:

• Windows 8
• Asus E45M1M DELUXE MB
• AMD Radeon HD 6320 Graphics Card
• HDMI
• Onkyo TX-SR875

Windows says my drivers are up to date:

• Driver Provider: Advanced Micro Devices, Inc.
• Driver Date: 27/09/2012
• Driver Version: 9.2.0.0

Can anyone suggest how to get this working?