I (personally) at this point would return your board for an RMA to the place of purchase or try to get the Updated
BIOS from DFI as there seemed to be a
RAM issue with certain CAS ratings of
RAM. I know this was the case with the T3RS as I had this issue with my Corsair
RAM.
Have a troll through the Living Review of the T2RS (Sorry, I just did, and it seems the T2R didn't seem to have the
RAM issue my T3RS did)
Failing the expiration of trying many different
RAM types, take it to where you purchased it and get them to do the testing and see if they can replicate the issue.
Did you get a RED light near the
RAM Slots?? If so, this would indicate that there is unwanted voltage feeding into the
RAM slots and this could possibly have caused damage upon the insertion of
RAM sticks rendering the slots useless. (this is a feature of the T3RS and I believe the T3 is just a DDR3 version of the T2.)
Clunk would be the man for a better explanation of your issue.
I hope you can sort out your problem.