I remember someone else recently had an issue with a ram kit on the newer AI300 series boards. They may just be a bit trickier on the timings that they will allow vs. the older processors. Kingston is a legit brand, just might have been some JEDEC timing that the board just did not want to POST with.
Seen lots of success with Cruicial, GSkill, and a few others. I would have thought Kingston would have worked just fine though the CL40 (or a subtiming thing) might be the issue.