Had a real similar problem just yesterday, Intel's XMP proflie set the RAM volts at 1.9 volts when the RAM was supposed to be 1.5 . would not Boot. So I coppied all of the XMP Profile , down on a pice of paper , than went to user defined , and set all the numbers the same except for the VOLTS and set the volts at 1.5 Booted right No problems since.
Are you just trying to set the ram to 1600, or are you trying to overclock the cpu as well?
Either way give the settings you are trying to use..
host clock frequency
turbo boost on/off
At a base clock freqency of 133 (although the 58XO reports 135) and a ddr multi of 8 would give the 1080 (8*x135), this would give a uncore of 16 (16x135=2160)
To acheive a 1600 ddr with a base clock would requier a ddr multi of 12 (12x135=1620) giving an uncore of 24 (24x135=3240).
Any changes to the clock freqency would then change the results.