Noctua NH-D14 not contacting LGA 2011 CPU

I am trying to install a Noctua NH-D14 cooler on a LGA 2011 CPU in an Asus Sabertooth X79 mobo. All parts are new. However, when I got the cooler, I accidentally bought a slightly older model that didn't come with the mounting kit for LGA 2011. Upon realizing my mistake, I went and bought the LGA 2011 mounting kit (also manufactured by Noctua) separately. Unfortunately, I've been unable to get the cooler's plate to contact the CPU when everything is assembled and screwed down. I know the foregoing for two reasons. First, when I boot into the BIOS setup, the CPU temp. immediately starts skyrocketing. Second, when I shut down the system and unscrew and lift up the cooler, there's no thermal paste on its plate; the blob of paste is just sitting there in the middle of the CPU. I went back and made sure all the parts of the mounting kit are fully screwed down, and I checked around and underneath the cooler to make sure nothing is obstructing it from screwing down completely, but to no avail. I can't get contact.

The only issue I can think of (short of some manufacturing defect or compatibility issue, whose presence I think is quite unlikely) is that I somehow got the wrong mounting bars included with my LGA 2011 mounting kit. In the image of the LGA 2011 kit on the Noctua website (http://www.noctua.at/images/products/fullsize/nm_i2011_1.jpg), the mounting bars, which are the long, curved bars on the left and right sides of the image, are completely flat, except for the screw head sticking up in the middle. However, the mounting bars I got with my LGA 2011 kit have a raised ridge along their outer edges, just like the mounting bars in my LGA 115x mounting kit do (http://www.noctua.at/images/products/fullsize/noctua_nm_i115x_mounting_kit_1.jpg).

I've never done a CPU/CPU cooler/mobo install before, but I have done numerous other hardware installs, and I really think I've done this right. Are the ridges on the mounting bars screwing me over? Am I missing something else? I would greatly appreciate any help for a CPU-install noob.