black dead line on the screen with dark colors displayed at certain site

[#1]

i have xperia neo gingerbread 2.3.4 kernel .62

i noticed a dark dead line on the top of screen which appears with dark colors for images . videos , games , applications ,,,, any thing falls in this site "i mean blue , red , grey , green ,.....",,, the depth of the darkness is proportional to the depth of the viewed color "i.e it ranges from faint grey to deep black ", i guess it's an issue of LEDs or something that couldnot emit those dark colors evidenced by not appearing with white or black

i uploaded a screen shot with arrows pointing to the line i mean

can anyone help ,,, i hope it's a software issue ,,, my phone is still in warranty period ,, if i sent it to warranty would they replace it with another brand new one or they will tell me that it's my fault and it was misuse

[Johan]

Unfortunately it's impossible for me to say but I suggest that you run a software repair via PCC and if it doesn't help you should contact your local support to have it examined at an repair center.

http://www.sonymobile.com/global-en/support/contact-us/contact-info/

[#3]

the cause of it is high temperature; display digrades. the only variant is to replace it((

[#4]

i just upgraded my phone to ICS ,, and noticed that this line is like a stamp of old screen "i.e. when it falls on dark displayed color , i can see this black line appearing as " 5:02 PM , and the signal of my operator "  ,,, i mean it sounds like a screen of notifications bar is frozen and displayed in the form of this line ,,, can any one explain ?