I upgraded my firmware from ess-6720-4 to ESS-6720-8 to help improve the macroblocking problem on dvd playback. Upgrade was successful. black level has been affected, picture has now become very bright so I had to re-calibrate my plasma with dv essentials. Picture seems to be a tad cleaner than before. Slightly more artifacts can be seen in dark areas which I had under control before but picture quality on background surfaces seem to have better control. Can anyone explain why my black level function when switched from normal [studio level] to enhanced [pc level] doesn't make any difference anymore? It used to make a lot of difference when switching between the two.