keefb:
This stuff is remarkably picky. I have the same software setup as you. You MUST have HDCP compatible videocard & monitor & you MUST be connected via HDMI. Even when you have this you must have your display set to 1920x1080.
Once you have all this set up it DOES work!
That's not entirely true. You don't have to use HDMI, you can use DVI and your resolution doesn't have to be 1080i or 1080p it can be 720p also. Also HDCP only matters for digital connections, so if you connect via VGA or component cables it won't matter if your tv/monitor or card are HDCP compliant.
As part of AACS content manufactures can enable ICT (image constraint token) to downsample analog (vga, component) connections but to my knowledge no one has started using ICT.