I had the same problem myself, couldnt get anything to work, more frustratingly couldnt find a pattern to the problem. Found this http://www.alternativerecursion.info/?p=797, which summed up my situation, changed to kingston memory modules and i`ve not had a reboot since. Theres a few other threads on here about random crashes etc which might help you out. (most to do with the turbo boost / speed step settings). IIWY id check your exact memory part numbers are on here: http://developer.intel.com/technology/memory/ddr/valid/ddr3_nonecc_udimm_results.htm.
Hope that helps you.