Gigabyte GA-970A-D3 with AMD FD6100WMGUSBX FX-6100 Processor and Corsair Vengeance CMZ32GX3M4A1866C9. I am attempting to upgrade the RAM from 16MB 1600MHz Vengeance to 32MB 1866Mhz Vengeance. Gigabyte website and user's manual state that 1866MHz memory (and above) can be used if an AM3+ processor is installed -- the FX 6100 Processor is AM3+. When the new RAM is installed the computer hangs in POST -- no errors. I then reinstalled one1600MHZ stick and the machine booted into the BIOS. I removed this module and reinstalled one 1866MHz stick with the same results ... hung in POST. Cleared CMOS and attempted it all again with the same results. (RAM checks out oh in a friend's machine.) What am I missing here?