Since the memory is correct for the board / processor and on the supported list.
I would check the CPU socket for a bent pin. Likely on the outside edge.
The pins are extreamly fragle and if the CPU gets slide sideways while installing it can bend a pin.
a minor bend can be corrected using a magnify glass and toot pick to gently push it back into position.
a major bend, is a mother board.
There is a photo in this POST to show what I mean. http://communities.intel.com/message/110489#110489
If you click this link (http://www.cmtlabs.com/mbSearchResults.asp?sManuf=Intel&sMem=DDR3&sMN=DG43RK&oSubmit) provided by Intel in their website for your board's third party memory you will see this note: Motherboard Alerts: DDR3 1333 Mhz speed will automatically be down-clocked to 1066 Mhz. There are two ram modules tested for such a board and they are listed in the link.
INTEL DG43RK Socket775, iG43, 4*DDR3, SVGA+PCI-E, SATA, ALC888S 8ch, GLAN, mATX
DIMM DDR3 (1333) 2Gb Samsung original - 2 pieces set
PROBLEM #1: motherboard do not recognize this memory.
It makes no boot, but gives error code by 3 beeps until power off. Neither with both modules together, no by one, in any combination on slots.
Another memory module (DIMM DDR3 (1333) 1024Mb Samsung original, 1 piece, I have no more) is recognized properly. Modules characteristics coincide, only volume differ. I’ve not found any info about this Samsung memory compatible on Intel site.
PROBLEM #2: BIOS upgrade failed.
There is 3 ways to do BIOS upgrade described on Intel site: from Windows, by F7 from USB flash card, from CD. All failed.
In all cases process of recording ROM is not observed, i.e. right after pressing «Begin» there appears «the upgrade process is finished successfully» window. No progress line at all. The number of BIOS version and date still remain RKG4310H.86A.0079.2010.0406.1853 04/06/2010. There is a jumper «BIOS config.», but it works properly according to the manual, and thus do not affects BIOS upgrade process.
PROBLEM #3: The system sometimes restarts by itself right after a logo Intel, i.e. prior to POST or in its beginning. I’ve found here <http://www.tomshardware.co.uk/forum/276689-12-problem-intell-dg43rk> a question on such a self restart in a forum but there’s no answer.
Such number and date BIOS is not present on INTEL site. There’s earlier and later ones. May be my case is unworkable version BIOS? What should I do?