Feefle

It happens with every game. I noticed that if there's a really dark shade on the screen, it's vertical plane shows a dim black line from top to bottom

The dark line in the middle of the treetop (One of them is circled in red), it's not supposed to be there

First post here. I recently purchased a gameboy pocket and noticed this: http://img248.imageshack.us/img248/1576/pockb.jpg There seems to be dark lcd banding in the trees, happens in a lot of places (But not on the main title screen). Wanted to ask about this because I couldn't find this problem posted anywhere on the internet. I'm using rechargeable duracell batteries 1000 mAh. Also tried to use a 500mAh adapter and still the same problem.