Reflection / Rotation Issue

Hey All,

I am trying to create a definition that gives me a plane that is perpendicular to the angle of the sun reflecting off the xy plane.  I have the definition set up so that the sun vector can rotate to account for sun angle and altitude, and the reflection is working properly in most cases, but in some angle ranges the plane flips orientation and sometimes jumps 180 degrees.  Also, when the sun altitude is too high, the reflection no longer works properly.

Since I need to create a bunch of panels, the rotation needs to be uninterrupted and the orientation of the panel needs to remain consistent.  I think this may be an issue with how the software is reading the angle input, but I can't figure out how to fix it.  I have tried radians, and also - and + angles.  Please see attached files.

Thanks!

-Joe