There is an incident where a user put about 16GB's of ram on an Asus Rampage X48 motherboard where Intel's specification sheet clearly states that they support a maximum of 8GB's of ram. The only catch with that users system is that it operated at 1333MHz and wouldn't boot when set to anything one MHz higher.
Your
motherboards specification page states that you can use DDR3 memory rated for 1333/1066MHz rated at 1.65v operation since it wasn't until Sandy Bridge came along where 1.5v kits became the standard. Mind you, if you're using a 32bit architecture for your OS then you should swap to a 64bit OS in order for Windows to recognize all of the available ram. The best coarse of action would be to source ram that checks out on your board makers memory QVL.