Please keep in mind the blue DIMMs needs to be populated first, after that try to isolate the problem on the memory or on the board. First, test each one memory sticks at the time on the blue DIMM closer to the processor and sees if it boots. If bout memory sticks work fine, try to clear the settings on the BIOS taking the battery out for 5 minutes then put it back in the same position, boot to the BIOS and set the data and time and give it a try with both memory sticks. Also you could try the system with basic configuration (no hard drive, no CD/DVD or card readers) and try with both memory sticks again. If it works fine start adding one part at the time and see if it works.
The problem has been resolved. The MotherBoard shipped with the original BIOS version which had a known problem with recognizing memory above 4GB. Ie I updated the bios to the current version and reinstalled the memory stick. Everything is working.