I have a Sony AGN-FZ38GU pre instaled with Vista Ultimate. I installed Ultra 9 sucessfully and after the patches all worked well. I then decided to upgrade to Windows 7 via upgrade rather than new installation.
After Windows 7 installation I continuously received the Error 0012 problem although the BD Advisor stated everything was ok.
I eventually solved it by going to the Sony Support web page and downloading the original Nvidia drivers for Vista and reinstalling. All works fine now and there is no 0012 error code anymore.
Not being an IT wiz, I believe that Windows 7 installs the latest drivers, such as Nvidia but doesnt take into account that some computers have specific versions of drivers for certain machine manufaturers. This seems clear when I went to the Nvidia web site to get the latest driver and it said I should get it from Sony. Therefore the solution is to try to reinstall your original drivers after upgrading to Windows 7.
I hope this helps others out there. I worked for me.