Certain aspect ratios cause the model to start disappearing with GL_LINE (works fine with GL_FILL)

When I resize the window to full screen(for example) portion of the image(cube via quads) disappear.
If I start with a window of full screen size, everything is ok.
The problem is when I use GL_LINE for polygon mode; GL_FILL is ok.
(Using OpenGL: 3.1.0 - Build 8.15.10.2509)
Any similar experiences?