On this mesh it's not very noticeable but on some of the others it was completelly messed up. THANKS !!! this solved my issue !!! I had to change it from 0 to 1.
I just select one of the edges and press Zoom Extents Selected (Z by default). That resets the clipping planes for the Perspective view, should solve it.
Try one of these shaders first, see if it solves your problem. http://wiki.polycount.net/Normal_Map#ShadersAndSeams If it doesn't, then rebake using some of the suggestions here.