I have the same problem with the same CPU, RAM, and similar motherboard (GA-Z68XP-UD3). I bought everything from Direct Canada, a sister company of NCIX (pretty much the same company, just different storefronts). Perhaps they received some bad stock from Gigabyte, who knows.
EDIT: I decided to check the CPU socket. It turns out it was 1 (read: ONE) pin that was off by mere microns, JUST barely noticeable to the naked eye. For some reason, it was shinier than the other pins - I probably wouldn't have been able to notice it if it wasn't. I was able to gently nudge it back into place. I knew how delicate these pins were the minute I lifted the plastic cover for the first time, so I know for a fact that I installed the CPU *very* gingerly. Thus, I'm reasonably certain that the socket arrived like that. It also appears to me that a majority of people with this exact problem have Gigabyte motherboards; perhaps Gigabyte needs to enforce better quality control on their CPU sockets. Of course, it's certainly possible that the bent pin was of my own doing, but considering that it was ONE bent pin, somehow shinier than the other pins, and that the socket was exposed for all of maybe thirty seconds before I gently put the CPU on top of it, I find this unlikely.
I have the GA-Z68XP-UD3 also. Bought it just before Christmas. I had the same problem. I checked out my socket after reading the post here and found a bent pin on mine too. I got some reading glasses on and used an exact-o knife to straighten mine out. Works great now. THANKS FOR THE FORUM POST!
Seems suspect that the same single pin would be bent on so many sockets. Maybe we all just bent it the same way, but what are the chances that ONLY that one pin that impacts the same thing would be bent by end users and none of the others. Seems like a QA problem to me too.
Anyway, happy I didn't have to RMA it. I did cross-ship RMA more memory before I found it was a slot problem. I guess I will just keep the extra 8 gig and use it. :sigh:
