As the titles says. With a material like this one:
What I get is: In the "material" view, the texture shows up fine, mapped like I want it to be, but in the rendered view, it's rendered in an average of the color of the texture (it's not just black, I tried another texture, a wood one, and the result was a shade of brown averaged from the texture colors). As you can see, though, the preview of the material shows up fine.
Instead, with a material like this one:
I get this: In the material view, the texture shows up but it's mapped incorrectly, BUT, in the rendered view, it shows up, but it's mapped incorrectly (obviously).
ALSO: I unwrapped another object (very roughly), applied the same shader as the first one (with coordinates set to UV) and the texture renders fine. What gives? And, it definitely is an average of the color, because I even tried to draw some red stripes on the texture, because I thought that maybe the render was fine and it was some lightning quirk, but nope, non of the stripes showed up in the render.