SGK

I'm have a semi-related problem. Before I installed SP2 I could play all my DVD's in PowerDVD 4.0 which is my preferred player. After installation of SP2 I can no longer play older DVD's such as the theatrical release of Lord of the Rings: The Fellowship of the Ring. However, I can play the extended edition which came out about a year later. So I uninstalled PowerDVD and then reinstalled it. I can play the newer DVD's but still cannot get the old ones to play. I get nothing but a black screen. I have: NVIDIA GeForce4 MX 420 card AC3 Filter PowerDVD 4.0 Samsung DVD-ROM SD-616T DVDRW IDE1004 WindowsXP SP2 Intel Pentium 4 2.40HGz Any suggestions? Thank you.