I've tried a number of screen tests with my nvidia card's plethora of outputs and resolutions, so I know it occurs on hdmi, dvi, component, and s-video. Also it can be seen on analog/digital cable shows and on null input. It looks better (both light and dark scenes) right now, but also the room is somewhat bright - I haven't installed proper blinds yet. Assuming it doesn't improve with some use over the next few days, I'll probably leave the set face down on a fleece cloth over the next weekend while I'm on vacation. Who knows how the front desk at my apt was storing it before I picked it up from them - that might even out some stress. I also ran a few pixel-excitation videos and programs while I was out. Once again, I'll have to wait for some better lighting to compare to what I was seeing last night. Calling Sharp first thing next week if it doesn't get any better by then.
Other than this, the monitor is fantastic. I get a couple dozen compressed sd and hd channels from the qam tuner (comcast fyi), but it seems to me that the analog tuner on this set produces a better sd picture than the blocky 480i garbage on some of the non-hd digital channels. Kind of a bonus, as I'll be tuning and recording analog cable and over the air ATSC with the computer anyway. Guess I can set those favorites buttons on the remote to anything hd that doesn't come in over the airwaves. I can see how the qam tuner would be a godsend to people who aren't so close to two major markets (DC and Baltimore) and have fewer OTA options.
I know the problem seems more serious to the kind of people who post on internet a/v science forums... like myself? Ha. Because overall the set looks damn nice after some time in the picture controls, and I wonder if less a/v oriented people would even see this as something out of the ordinary. So in the case that the repair would be very expensive or not available, I'll sell the set at a discount to one of the local kids and put the cash toward an identical replacement. There's plenty of market for it here, and I would be uneasy about selling a set with a possible performance issue to a non-local with only pictures or descriptions to back it up. I'm going to continue tweaking and working on control/recording/playback through firewire with my pc and hd-camcorder. Get them to at least tolerate each other, and maybe even play nicely. My goal would be to shelve the remote after calibrating, and control everything via RS-232C. By now all I do is input switching among the inputs while doing audio passthrough anyway.