Have just run into this same problem. Was populating my other 2 memory slots to try and play COD Ghost. Had added this memory before, so I know that the setup works. Went into the BIOS (990FXA-UD3 rev. 4) to make voltage settings and set memory timings to auto. After that couldn't get it to completely boot to the BIOS.
Spent 4 days of pulling the Cmos Battery, changing the jumper, disconnecting any kind of USB devices or fans to try to get it to boot into the bios.
Woke up at 4:00 am Saturday morning and pulled Mobo out and replaced with a Asus formula V that I think had VMR problems. (works good enough to browse but not game).
Found out I need to pay $ XX.XX amount of dollars for them to fix the Mobo that has a "Dual BIOS": FEATURE BUILT INTO THE DAM MOBO SO THIS WON'T HAPPEN.
Sorry, it's a contradiction. Theft by deception. Thought it was a good Mobo.