When watching the Alias Season 2 DVD on my Panasonic SA-XR50, I noticed that the subwoofer wasn't playing. After playing around with the settings, I figured out that the sub would only play if either the Fronts were set to 'small' or the Center was set to 'small'. I then tried some other DVDs and I was able to get sound from the sub when everything was set to 'large'. I made sure that Sub was set to 'YES' in both option 1 and option 2. Has anyone else had any problems with this DVD?