Immage not centered and dark corners on pictures

If it's done it on two different bodies than it may be a lens issue(slim chance). Try another lens on your body. Sony also uses a movable ccd instead of moving optic for its image stabilization and may be a bad design and really prone to screw up. I would lean toward a super steady shot problem and the ccd is not lined up right. Personally I've not been impressed with anything sony for a long time, when it comes to DSLRs the only real choices are Nikon or Canon. They own the market and have all the experience and product lines to back it up. In recent years build quality has leaned toward Nikon. I would make sony fix it and then sell it asap before it does it again, then buy something more reliable. Just something to think about.