This problem started almost a week ago and can't think of any reason at all
the thing is that when I listen to music, recharge the battery or use insomnia all this with the phone on sleep/lock the screen starts to fill with vertical grey-black lines and if I "turn on" the lcd and off again they go away to come back again in about 2 mins as if the phone doesn't enter complete sleep mode and the lcd keeps receiving electricity from the process running in the background
(if I enter sleep/lock while idle the lines doesn't show at all)

the device is iphone 3gs 16gb old br
tried 3.1.2 and cf 3.1.2 and cf 3.1.3

any help would be greatly appreciated since I don't have any kind of apple service or support in my country