mythbuntu 14.04 - black & white on TV with Geforce 8600GT


My previous mobo in my mediaplayer gave up so I decided to get a new one.
Unfotunately the new mobo has no ata ports anymore (its an old HP/Compaq workstation) so I had to perform a new mythbuntu installation.
Everything went well until the pc got connected to the tv. I installed the 340 driver from Nv’s web, ran the .run installer.
The system started up on monitor but gave black screen on TV which I could corrected by editing the xorg.conf.
Since then I got picture but with issues:

  1. The screen is off border in every direction.
  2. The screen is grayscale no matter I do.
    It is very annoying, because with the 295 series it worked like charm out-of-box.

Any advice?

Thanks in advance

How is your TV connected to your graphics card? For old-school TV encodings such as composite or S-video, overscan borders are expected. The grayscale issue sounds unexpected, though. Can you please generate and attach an file?