Problem with the 1d Mk IV

Has anyone had any problems with the new Mk IV? I have this camera and recently started having significant problems with verticle lines showing up in the images. These were noted both on the computer, and, upon closer inspection/enlargment, in the screen on the camera back. I changed the memory cards, tried different lenses, resolutions etc and it kept occuring. I have sent the camera to Canon (2 days ago), and so I have heard nothing back. Prior to this problem, I had abdolutely no problems with this camera and was amazed by its high ISO performance. I look forward to any input, and will give a follow-up after the repair.

Tom