Sumvision sv-1000

hi hope i am in the right furum i have the sumvision sv-1000 when i plug the scart from the sky box to the dvd i get a gray vertical line running from right to left people at bigpockets say it is a frequency problem and to see if there is a way of changing it on the dvd if there is how do i do it or what is the best frequency to set the sky box to.thanks