I dont wanna get flamed down here - but firmware probably wont help!!!
This is a new version of DVD Protection that Sony are implementing - It was allegedly only theoritical when I heard about it a while back - but looks like it has made retail already!!!
This will be loosely based upon the new SecuRom protection...
As you are using Writeable DVD drives it wont play - I bet if you put it in a normal DVD-ROM drive it would play on your PC fine..
They seem to have gone crazy on writeable drives and are persecuting both CD-RW and DVD +/- RW drives - I had to dig an old DVD-ROM out just to get a Sony product working!
Please keep us informed of how you get on!