Picture display distortion when using HD

[Jo26]

Every time we watch TV on HD channels the picture distorts with coloured lines flashing across the picture which means we have to change to a none HD channel. This is annoying when paying for HD and then having to watch live sports on a normal channel.  

[Mark39]

A couple of things to try:

- check that you have no picture 'enhancements' turned on in your TV settings, and

- replace the HDMI cable.