DX58SO will not boot with memory in channel C with I7 975

I am on my third motherboard and I have not been successful in having one boot with memory in Channel C.  The only item connected to the board is a low end graphics card.  I have tried several versions of the BIOS and different memory chips. I am using Kingston KVR1333D3N9K3/6G which Kingston assures me is the same as KVR133D3N9K2G.  The difference is the first number is a set of 3 matched modules for a total of 6GB.  The system boots with memory in DIMM 0 Channel A or Channel B or memory in both Channel A and B but whenever a chip is placed in Channel C it will not boot. When the system is turned on with memory in channel A o B the fns spin,the video comes up and they system go to the splash screen,  With any combination that has something in channel C the fans spin up and then stop briefly as if the system were rebooting then they stay on but I never get any video. If I remove that memorny from channel C everything is fine. There is no memory installed DIMM1 Channel A.  The Intel Techs are saying the board version E29331-501 is fine with the 975. A lot of finger pointing going on here but no answers.  Other things I did – Clear the BIOS, reflashed with 3044, 4014 and 4158, changed video card , changed memory. Anyone ever see this?  Since the system works fine with 4GB of memory in Channel A and B I would guess the processor is OK. I am now leaning toward the idea that I have a third bad motherboard board.