I have noticed that when viewing programmes using the internal Freeview digital tuner in my Sony KD28DX50U, vertical bars are visible across the screen. These bars are green in colour and are separated by approximately 2cm gaps. This problem is not present when watching ntl cable, DVD, or VCR. Has anyone else seen this problem, and if so how was it resolved. I'm due to have a Comet engineer come out to see the set next week and would like to have an idea of what the problem could be before he arrives. Thanks in advance for your help.