just had found that bank 2 also works. so, i have memory in 2,3,4, but not in 1. the latter does not work.
Not sure if this is related. I have the DP67BGB3 mobo and have been running gskill 1600 16g (4gx4) never had a single issue even running stable at 4.5ghz without a sweat. the bios I was running was revision 2040. I just updates to the revision 2076 and it has literally been hell. 3 long beeps. constantly. can not over clock at all without shutting down. just reflashed back to the revision 2040 and my memory is back to the normal and running at 1600mhz. with revision 2076 I could only see the 1333 from memory if and when it decided not to give me 3 beeps of death... try that out and see if it helps.. The only reason I was updating bios was the added activation 3.0 for windows 8 ... let me know if that works if you are running the latest bios. if so then Intel needs to look into this)