Yes, there has been a report about this phenomenon earlier. The contour disappears in case you set the thickness of the "side wings" to zero. As a workaround I suggest you to set it to 1mm.
I scheduled a fix of the 0-thickness for AC14.
Sorry for your inconvenience!
Zsolt Táskai
ArchiCAD Development - GDL Team
AC13, AC14 and upwards...