If you use the Environment Preview, it's about 90 degrees off from the background. You can set it at a U_offset of 0.25 to have it match the rotation of the background for a visual and then hide/delete it for the render. Keep in mind the rotation in the Mapping node is in radians rather than degrees.

---

Available on Amazon for the Kindle E-Reader Monster of the North and The Shimmering Mage

Today I break my own personal record for the number of days for being alive.
Check out my store here or my free stuff here
I use Poser 13 and win 10