How to get rid of hidden lines displayed in shaded mode

As the screen shot shows, the shaded mode displays like wireframe mode but with the surfaces. I’ve tried re-installing the program, restoring the defaults for all the display modes, downgrading my graphics drivers, and turning off anti-aliasing. If anyone has any other thoughts they would be greatly appreciated.

Hi,

What is the graphics card in the machine? AMD by any chance? If so, this could be your problem.

–Mitch