I had a similar problem with my current drive - what I did was this:
I set AnyDVD to NOT run on Windows start (in the AnyDVD settings). Then I rebooted &, lo & behold, I was able to go to the device's properties & then Region tab & change it to the correct region (with a region 4 disc in, of course - my region!).
After rebooting again & confirming that the region was still set, I re-enabled AnyDVD & set it once again to start with Windows. Then I checked the region setting again & it was, & still is good.