Panasoinc Plasma Purple line bottom of sceen?

I played a full screen dvd on just mode on my 42 inch plasma tv, and there is a flickering line at the bottome of the screen..It varies in color from white to purple to pink. I use component cables from my dvd player to the tv. Does anyone know what the problem could be or how i can fix it. When i swithch to 4:3 or zoom..I don't see the line...


Thanks