I can also confirm this issue: Tested with 4x, 3x, 2x and 1x kvr1333d3n9/2g.
With more than one, i do not even get the 'Visual Bios' screen reliably. When only one of the 2G Modules is installed, I get the Bios, can set some settings inside but booting from UEFI does not work reliably. In most of the cases, the machine hangs until I press reset.