I bought a xfx nforce 790i ultra sli motherboard and 4 "corsair xms3 – 2048 mb 1600mhz" memory stick. the system will run fine with 2 memory sticks in DIMM Slott 0 and DIMM Slot 1. Place all 4 memory sticks in the the computer and the system wont start. When I power up I get a series of long beebs with a Post Code C1. Not sure what needs to be done.