its wierd that you cant do 1200mhz with your dominators, mine do it @ 2.3v pretty easily, although my system is pretty unstable as a whole when i run a 5:6 divider so i like to keep mine 1:1... theres really not that big of a performance difference... pics

1:1 ratio @ 533x8


and now the 5:6 @ 500x8


as you can see i get better write/copy speeds @ 1:1 with only a 300mb difference from running @ 1200mhz, timings on both are 5-5-5-15-2T as you can see, so im stickin with 1:1 until the stability fairy comes and taps my comp with his wand.