Hello,
I have the mb DZ68BC [0037 BIOS; S1155 Intel Core i5-3470]. Also I have a special addition: I mean proper behaviour of RAM banks 
When I insert 4 DIMMs [Corsair 4Gb 1600MHz PC-12800 Vengeance :: CMZ4GX3M1A1600C9B] MB detects only 2 DIMMs (1st RAM bank :: blue). Another RAM slots marked as "Not Installed" (black). And BIOS shows me only 8Gb of RAM.
Ok, I ejected blue bank and started computer again. Impossible 
! I saw 2 DIMMs in the 2nd bank (black) which have been marked as "Not Installed" a few minutes ago.
What should I do? I really want to have 16Gb of RAM which I bought :).
Thanks.
P.S.
Can anybody post here a direct link to Intel support form or mail where I can post my problem. I tried to find it by myself but had no any success