Problems posting to BIOS tripple channeling

[loki5]

Hi all - my buddy is in need of your help. Connected everything up tripple channeling and system does not post to bios. We then checked each memm stick in slot DIMM 1 and all three mem sticks for either G.Skills or Corsair posted to BIOS fine. DIMM3 did not post with any sticks. DIMM 5 all memm sticks posted. DIMM 1 & DIMM 5 posted to bios just fine with all memm sticks. We've cleared CMOS multiple times.

Additional process of elimination:
Motherboard was RMA's
CPU i7 920 was exchanged (thought was the mem control was defective)
We tried with the stock cooler and Titan Fenrir hsu.

Solutions:
Could this be bios related? Should bios be updated? Should we change any of the settings to DRAM. (we also up'd the DRAM volt to 1.65 and changed speed to 1333mhz)
We really dont know what else to try.

Note: When we spoke to a tech support yesterday, prior to swapping processor to confirm it was not a memm control issue, he did state the mobo we had RMA passed RMA check points and the board was fine.

Here are some screen shots of BIOS settings

CPU: i7 920
Motherboard: eVGA 758-TR
GPU: XFX 5850
Memm: Corsairs 6B PC1600 TR3XG1600C8 G
Memm: G.Skills Ripjaws 6GB PC1600 F3-12800CL8T-6GBRM
PSU: Corsair 750TX