I think I remember having to hook my ps3 up using component cables and messing with the output settings to get HDMI to work on my HDTV. It was awhile ago though and the only thing I use it for now is to kick my feet up when using my computer.
That makes sense. Component can display HD video and was around before HDCP existed. If you change the video cables, you need to change the ps3's video settings first, in this case component.