The patch does work on an Oppo 981. Thanks Crometus and thanks to Neuromancer for discovering that it works on the 981.
My plasma is HDMI and HDCP compliant but I patched the Oppo firmware anyway. Why? Because I hate DRM?

Because HDCP is a pain in the butt.
When I play a SACD, the Oppo navigator display is ugly and I don't want it to burn in on my plasma. So, after I start up a SACD, I switch the plasma over to digital cable and mute the sound on the TV. That way I can listen to the (non-HDMI) SACD and watch HDNET or DiscoveryHD or PBS HD or ESPN HD with no TV sound. But everytime I change the channel on the digital cable, the plasma thinks it has to renegotiate HDCP with the Oppo and the SACD sound cuts out for a half second.
Think about that. Because those Hollywood lawyers treat me like a criminal and force me to use HDCP, now I can't listen to a disc and surf the channels on TV without getting aggravated. Am I breaking any laws here ?
I soon found that I could set the Oppo to HDMI audio off and the HDCP won't re-negotiate. But if I do that, every time the wife or kid want to watch a DVD, I have to turn HDMI audio back on in the setup menu. Thats a real pain in the butt. Much easier to get rid of HDCP altogether now that it is possible.