I have a set of 2x8 gskill ares 1600 as well, and my set is really really picky about settings. It wont overclock at all, i cant tighten the timings at all, and it also doesnt like the default speed and timings my board defaults it to for 1333 cas 9 when i clear cmos. Once i set the primary timings to 10-10-10-30-2 @1600 its fine though. If you can get into the bios after you clear cmos manually set your primary timings rather than leaving them on auto when you set it to 1600, see if that helps. My set wont even post with cas9 at 1600, and is woefully unstable with a 1t command rate instead of 2t, even though its only two sticks.