Sanyo TV one scart socket seems grainy

[WILD9]

Ive got this sanyo tv. It has 2x rgb scart sockets on the back one of which supports s-video, when i plug my dvd player/anything with a decent picture quality into the one which supports svideo i get a really crisp picture both when using svideo input and rgb input. When i do the same on the other socket the rgb and composite picture seems a little more blurred and there appears to be some grain in the image, is this usual?