QUOTE(SPARCT @ Dec 4 2009, 05:51 PM)

Is it the same drive type? Did you inject the key from the old drive into the new one? It sounds like the key was not added into the new drive, which causes the symptoms you are describing. A incorrect or missing key will play DVDs without any problem but will not play games of any type.
If you did inject the key properly I would recommend hooking it back up to your PC and verifying that the key was copied over correctly.
ya sparct is right you probably did not get the key transferred to this drive.