UV seams? Smoothing groups? Non-normalized UV islands? Also, don't look at your normal map in diffuse since it's useless at helping your debug stuff, stick in your normal and throw in a quick spec + diffuse to see if the lines are really noticeable or not.
uv seams are not present there , smoothing groups are smooth and set to 1 on that area, whats non normalized uv islands? I added the pic of the normal map but actually I have some strange black linees on the diffuse , this is what made me check the normal map then I saw those linees and I got the picture ...