Hello. Small query. I have my Grundig digibox connected via s - video to a Sony KV28FX65. While watching sky digital broadcasts i sometimes notice a vertical white line on screen about 2/3 along (left to right). The line is not always visible. but causes minor irritation especially on dark scenes where it can spoil the overall picture. Would simply purchasing a higher quality cable eliminate this problem ? Or is there something else i should be looking for. The cable i currently use is a rather inexpensive number for about £10. Any help greatly appreciated.