you might seriously consider trying another media player, I use media player classic, and have no issues with codecs, the other nice thing about MPC is that you can use it to play back real media, and QuickTime using a couple of plug-ins, if you want to know more about MPC, PM me, and I will send you a link. As far as service pack two goes, I think you are pretty safe in upgrading to it. Also I forgot to mention MPC is a free program. Hope this helps