I guess I can't catch a break with this thing!
I just had to revert my second device back after I noticed that it had a big dust particle stuck under the screen. It was very noticeable when viewing anything on a light screen. I'm not sure how I missed it, unless one of the pixels died after some time. Oh well, back to the store again tomorrow! I never thought I would shop at Bed, Bath, and Beyond so much...
This time I'll just exchange it for another, and hopefully give the screen a thorough run through before I hack it again!