I’ve some how managed to solve this problem today
Not sure which of the following sorted it but this is what I did anyway.
1st I downloaded Omnipatcher v1.3.18 and firmware version US0Q
I applied the recommended DVD media tweaks and applied all General Patches exept for the force-fallback patch.
Now I flashed the drive Using Firmware Flashing Tool v1.0.0
I should have tried the drive again at this point, But I didn’t. Sorry.
Then I uninstalled the following software: AnyDVD, CloneDVD and PowerDVD.
Next I looked at the driver files the drive was using in device manager, made a copy of them then deleted them from the system32 and system32/drivers directories. then I uninstalled the drive in device manager and rebooted the pc.
Once it rebooted I got a message asking to reboot again because some registry settings had been changed (should have made a note of this but I didn’t sorry.), I did another reboot.
Then I put in my queen of the damned DVD and was presented with a InterActual Player setup, I wasn’t aware of the software on the dvd, but I allowed the install anyway.
After the install the dvd played fine
Tried another DVD just to make sure, which is playing fine too.