Can you revert back to the old firmware? If not, you might want to check out http://forum.rpc1.org/portal.php They have custom firmware for several optical drives, perhaps yours is one of them. You are supposed to be allowed to change regions a few times on a drive, but to be honest I've never done it so I can't really say how to fix it. I would imagine that if you can't revert to the previous firmware or find a fix on the above listed site, you would need to uninstall the drive and re-install it, find some kind of registry hack or reinstall the OS (not a viable option if you ask me, dvd drives are cheap enough that I wouldn't even waste my time)
2 x Xeon e5520 | Asus Z8NA-D6C
12 GB G.Skill DDR3 | Radeon 5850
Corsair 128GB SSD | WD Black 1TB HDD