PowerEdge T610 BIOS in disagreement with documention and iDRAC about memory configuration.

I have a situation where the BIOS is not recognizing a documented valid configuration for installed RAM and I can't turn on the "Advanced ECC" memory configuration setting. How do I enable "Advanced ECC"?

The documentation (http://downloads.dell.com/Manuals/all-products/esuprt_ser_stor_net/esuprt_poweredge/poweredge-t610_Owner%27s%20Manual_en-us.pdf) lays it out pretty clearly that "Advanced ECC" memory configuration requires that the memory sockets (A1,A4) and (B1,B4) are to be empty, and that the remaining sockets (A2,A5) (A3,A6) (B2,B5) (B3,B6) are to be configured identically with appropriately spec'd ECC RDIMM memory. 

In addition, the iDRAC does not report all of the memory in its System Inventory > Hardware Inventory. So I guess I'm dealing with multiple bugs on older deprecated, but perfectly serviceable and useful Dell hardware?

The screenshots below pretty much tell the story.

(1.) Photograph showing memory slots (A1,A4) empty while (A2,A5) and (A3,A6) filled. These are 4GB DDR3 ECC RDIMMs purchased new from Dell.

(2.) Photograph showing memory slots (B1,B4) empty while (B2,B5) and (B3,B6) filled. These are 4GB DDR3 ECC RDIMMs purchased new from Dell.

(3.) During POST the BIOS is 6.4.0 (latest)

(4.) During POST 32GB is detected, but message "Warning: Unsupported memory configuration detected. The memory configuration is not optimal. The recommended memory configuration is: (A1,A4) (A2,A5) (B1,B4) (B2,B5) filled with (A3,A6) and (B3,B6) empty.

(5.) F2 is pressed for Setup, so the Memory Operating Mode can be changed from (apparently unsupported) "Optimizer Mode" to the desired "Advanced ECC". But the Memory Operating Mode property of the Memory Setting window in BIOS Setup is protected and cannot be changed! Tried to do a 2nd power off (to double check memory sockets in use), but the 2nd restart still did not allow updating this value. The security settings are all off in BIOS. Why can't I change this?!

(6.) The next boot capture screen shot is ESX loading, and detecting 32GB. What is not supportable and optimal about the layout of the DIMMs? We prefer "Advanced ECC" for ESX, but if that is not possible due to unresolved software bugs, what is the best configuration of DIMM sockets to provide best performance to ESX?

(7.) The Dell iDRAC on this PowerEdge T610 does not report all of the installed DIMMs (it only reports 4 DIMMs, 16GB) in sockets B1, A1, B2, A2. Why doesn't the iDRAC show all of the sockets? And why is it claiming there are DIMMs in B1, A1 when we know absolutely with photographic evidence that B1 and A1 are EMPTY!?

(8.) I've provided a screenshot of the installed firmware. Are these not current and up-to-date?

(9.) Interestingly, ESX, using hardware drivers for Dell PowerEdge, correctly reports the hardware status and the location of the installed DIMMs.

In a reply to this post I am uploading numbered screenshots (1.) thru (9.).