There is a thread here about hacked firmware to make drives region free. However, it is very old and none of the newer drives are included. Where can I get such a thing for newer drives?
You can check the firmware page and see if anything is listed for your make and model. Not free but there's AnyDVD and DVD Region+CSS Free software that makes the drive region free when running.
What drive do you have? http://codeguys.rpc1.org/ http://liggydee.cdfreaks.com/page/en/ http://tdb.rpc1.com/