2 lines? you mean in the NEC graphic? those are just sposed to be like graphs and stuff, apparently they were trying to attract small buisnesses or something...
jeez, i dunno, i doubt you'll see it or even care, especially if playing games or movies,
im sure there's a fix if it bothers you, and it might only come with some monitors, if you just plain won't buy cause of that, then maybe think about a 20-22"