Thompson DTI 6300 jumping/stutter/sound and video?

Hi,

Just wondered if anyone else has experienced this problem since the digital switchover, its a pain, I cant watch TV, I can't record anything and it's driving me mad, anyone know how to fix it, ive done constant retunes, reformat, software revert, I should think the problem is more signal, checked the aerials, nothing wrong with the lines all clear and as they were.

Any body have the problem and cure?? Thanks