I haven't restarted the server, but I just remembered which slots is being used:
DIMM 3, 1 (channel A) and 4 (channel B). (see item 5 for explanation: http://downloadmirror.intel.com/20956/eng/dz77ga-70k_IntegrationGuide02.pdf)
All memory modules are of type CMZ16GX3M2A1600C10. (Corsair 8 GB modules)
Grrr, hate that such a hightech board does not support this! Again - Intel - go fix!
I RMA-ed my entire kit to corsair and got a new one. Without changing a think except enabling the xmp profile in the classic bios config it now works @1600MHz. No beeps or anything, not even once.
There was either something wrong with the modules after all or there is an incompatibility between the DZ77BH-55K and earlier versions of these dimms. Maybe this is even an accident. Maybe I got dimms using ic's from a different manufacturer. Less bus capacitance or so.
Whatever the reason, I'm glad it works now.
i just upgraded BIOS to version 0059.
it is still not working. i have checked all my RAM pieces and every single one is okay, so now it's either a failed BIOS or the two empty RAM slots were manufactured in some crappy way making them useless.
either way, nice going intel. i will NEVER buy any of your products again.
Any response or cure from Intel regarding this problem? I'm trying to get a DZ77GA-70K board set up w/ the i-3770k processor but having similar start up problems due to memory errors and 3 beeps (error code 41). I have 2 8gb Kingston 1600MHz sticks, they only seem to work in DIMM slots 2 and 4 (two farthest from CPU), and only able to run single channel. I tried each stick one at a time in each of the DIMM slots and only 2 and 4 are working. I have latest BIOS installed and have tested other BIOS numbers as well.