3 pixel color changing line at the bottom of the screen

[Ithilion]

Hello, i'm on a 250 gts and i'm using a samsung le19a656a1d (1440x900).
My problem is i have this 3px line at the bottom of the screen that keeps changing color whenever i change monitor source or turn monitor off/on. The line is not present at pc startup but it appears when desktop loads
Thanks in advance for any support and sorry for my english.

 

[Ithilion]

I forgot to mention i'm using a dvi->hdmi cable (dvi at graphic card, hdmi at monitor), and that the line does not appear on any other source (tv)