Ellipse-spline center line displayed

Hi,

I am not a guy of 3dsmax; I use it for rendering the PCB boards before the OK to the production.
Installed the 3dsmax 2014 (with the 2012 all OK).
The ellipse and the spline, when zooming -, display the center wire into the "Realistic" windows, like the "Wireframe" windows.
When zooming +, the wire is ate by the thickness of the ellipse/spline.

What is it changed ?, what I must do ?.

Thanks.

amelia