I've seem that back with my first H20, which caused me to shift to black pillar bars. Doesn't it also vary with the channel your viewing? "I think" it comes from the SD channel not being "full pixel" and the pillar bars starting a the 640 mark? If this is the case, then the SD program needs to be scaled to the full 640 size so the pillar bars fit, or the pillar bars need to trim some of the SD image. [much like overscan]. This may not be it at all, but "what I thought" when I first saw it.