Short description of error
The Sun light type, is not taking the appropriated rotation and when i render the scene the light is targeting almost in inverse orientation of what a specified in the rotation of the object in Cycles engine.
Exact steps for others to reproduce the error
Add a sun light object in the scene.
Add a box in the scene.
Add a camera in the scene.
Target the box with the camera object.
Choose a direction for the sun light object by rotating it.
The Sun light should render the light somewhat in a different rotation than specified, especially in the Z rotation. It also cause problems on the XY rotation and does an inverse rotation when they go to negative values.