I noticed this, and I have been posting topics all over then net, to see that I am not the only one with this "problem".
Well the issue in it selv didn't bother me, it bothered me to think that not everyone had this.
After many posts on different forums, it seem there are two opinions on this matter. They who see it, and they who don't bother to look that closely, and just through out their anwser: YOUR GBA IS FAULTY- GO GET A NEW ONE, MINE IS PERFECTLY FINE!!!!