Recently purchased Sony KV-32FQ70. Intermittent problem with a thin horizontal line of approx 1 - 2mm thick appearing on screen. The line is the same colour as the background (more obvious in light backgrounds) with "greyish" edges. Sometimes there can be two lines. The line(s) are not always in the same position - e.g. last night the line was showing up on BBC1, ITV and C5 all at different positions on the screen. Does anyone know if an aerial fault or weakness can be the cause?