Share your experience!
Hello there
It appears that your TV has developed a hardware fault. The first port of call would be to contact an authorised Sony Repair Centre to get this fault diagnosed and repaired - see link below
http://www.sony.co.uk/support/en/repair/asc
However doing a quick search around, it appears you are not the only one that has this fault (links below). Unfortunately I dont have the time at the moment to go though all the theads, but it seems that the Timing Control Board needs replacing.
http://community.sony.co.uk/t5/Televisions/KDL-32D3000-multiline-screen-fault/td-p/186218
Cheers